Monday, December 22, 2008

Recent ACE Prep Class in Houston

On December 11 I had the privilege once again to participate as an instructor in the 5th Associate Certified Entomologist (ACE) prep class offered in Texas. As with previous classes, the course was sponsored by the Texas Pest Control Association and taught by myself and Dr. Bob Davis of BASF Specialty Products. This class was also co-taught with first-time lecturer Dr. Grady Glenn, pesticide applicator training specialist with Texas AgriLife Extension Service.

As any of the participants will tell you, this is a classic cram course. We cover topics ranging from a brief introduction to entomology and insect classification, to toxicology, laws and regulations and overviews of cockroach, WDI and rodent biology to just name a few. The pace is quick, but fun as the class interacts with instructors and gets a few pointers about test-taking.

The purpose of the class is to prepare participants to take the challenging ACE exam, one of the prerequisites for becoming an Associate Certified Entomologist. At the end of about 6 hours of cramming we offer the exam to anyone who has applied through ESA and registered to take the test that day.

I enjoy teaching this class because of the quality and enthusiasm of the participants, each of whom must have seven years of experience in the pest control business. The other thing I value, and I think participants do too, is the opportunity we have to review fundamentals--the whys behind many of the little rules and facts we learn in pest control. It's a chance to dig a little deeper than the typical CEU class, and much deeper than technician training.

Of course taking the class is no guarantee of passing the test. Our pass rate is typically 50-60%, though this class had a nearly 90% passing rate. We find that success is highest for those who review the study subjects prior to taking the class and exam. But most importantly, we find that the pass rate is 100% higher for those who take the test than those who think about it but never get around to signing up.

If you've thought about certification, but hesitate at the thought of taking a tough exam (it's been a long time for all of us since our last final exam), consider taking one of the ACE prep courses being offered around the state. The next class and exam will be offered at the B&G Chemical and Equipment Company workshop in Arlingtion, on January 22. Note that the Arlington venue is the only B&G venue that will be offering ACE prep training this year.

To learn more about the ACE or BCE certification programs, check out the Entomological Society of America's website at There are no official study guides, but the website offers a very detailed list of the subject matter that is covered by the exam. Two of the best study resources I recommend include the Truman's Scientific Guide to Pest Management, and the NPMA Field Guide to Structural Pests. I suggest focusing study time on topics you feel a little weak in. Stored product pests and pesticide classification are two subject areas where many applicants seem to struggle. Also, definitely take the sample exam on the ESA website. It gives you an authentic taste of what the real exam is like.

Successful candidates receive a certificate and uniform patch and earn the right to advertise themselves as Associate Certified Entomologists. In addition, ACEs receive the ESA Newsletter and have the option to register for ESA journals and meetings at discounted rates.

Congratulations to those of you who recently took and passed the exam. I look forward to seeing many more of you join the ACE ranks in the near future.

Wednesday, December 10, 2008

Look out for signs of drywood termites

A pile of drywood termite pellets at the base of this roof joist spells troubleDrywood termites are not a common problem in many parts of Texas, except along the coastal bend areas from Port Arthur to the lower Gulf coast. Nevertheless, drywood termites can show up anywhere in the state. For this reason, PMPs should always be on the alert for signs of these insects.

Drywood termites belong to a different insect family (Kalotermitidae) than the more common subterranean termite (Rhinotermitidae). One of the differences in this family is that all colony workers are immatures, and there is no true worker caste. Another difference is these termite's ability to conserve water and live with no direct soil contact.

One of the best clues that drywood termites are present in a home is the presence of many tiny, six-sided fecal pellets that are ejected from the colony by the termites, or which spill from damaged wood that has been exposed by probing or carpentry activity. The pellets themselves are easier to spot than the ejection holes; but once found, ejection holes can be used as a portal to inject foam or liquid termiticides into infested wood.Drywood termite pellets caught in a crevice above quarter-round molding.  Attention to detail, sharp eyes and a good flashlight are essential for spotting  signs of drywood termites.

Fecal pellets are often less than 1 mm long, and vary in color from light tan to reddish to black. Surprizingly, the color of the pellets seems unrelated to the color of the wood on which they feed. Look for pellets along molding in living areas, when conducting attic inspections, and around window areas. Wings are another sign of drywood termite activity. Look for termite wings in window areas or spider webs in the corners of attics or Drywood termite swarmer wings on a pull-down ladder to the attic of a home in Dallas, Texas.rooms.

Just because you've never seen drywood termites in your community before doesn't mean they aren't there. Away from the more temperate, humid areas of the state, where they swarm and spread naturally, most drywood termite infestations are imported by humans via furniture or construction lumber. Because these termites reproduce and feed more slowly than subterranean termites, it may take many years for the colony to mature and begin producing swarmers.

Drywood termites are a good example of a pest that may or may not be seen frequently in your area, but one that all pest management professionals should know something about. Keen eyes and an ability to spot things out of the ordinary are skills that will help separate you from your competition.

Tuesday, December 2, 2008

Bed bugs pose threat to schools?

Some school districts are beginning to worry about bed bugs. About a year ago the Bracken County School District in Kentucky closed their doors for a day to make sure no stray bed bugs were left behind following a find of a single bed bug in classroom. The bug was supposed to have come from a student whose home had bed bugs.

This week the Columbus Dispatch, in Ohio, reports another panic over bed bugs in school classrooms. According to the article, "Researchers and public-health officials fear that tiny, brown, blood-sucking bedbugs are going to spread through schools."

Greg Kesterman, director of the environmental health division for Hamilton County Public Health (Cincinnati, OH, where bed bug problems are growing quickly) is quoted in this week's story as saying, "Anytime an insect has the potential to crawl on a person, and travel with (people), you're guaranteed that you'll see them showing up in a public facility." This is certainly true. Bed bugs have, and will, show up in schools from time to time, especially as infestations in homes become more common.

What I question is the followup worry that steps need to be taken to avoid a "large scale problem" in schools. Are bed bugs really another problem that schools need to be highly concerned about? I doubt it.

While you never want to underestimate nature's ability to cause mischief, the threat of bed bug infestations in schools should be minimal. Bed bugs are principally active in the dark (except in cases of heavy infestations--which would not be the case with the occasional, stealth introduction to a classroom). After dark they need a reliable source of blood to sustain a population and spread. Since people generally do not sleep in classrooms (with possible exception of short afternoon nap times in pre-school rooms), it would be tough going for a bed bug that slipped out of a backpack into a typical classroom from an infested home.

In my estimation there is little risk of actual bed bug infestations requiring treatment in a public school classrooms or auditoriums. Dorms are another issue of course. Also, the risk of one or two bed bugs emerging from of a child's backpack and infesting other kid's belonging is conceivable, but the risk is also probably low. Should PMPs, school nurses and school pest management staff know what a bed bug looks like, and something about its biology and behavior? Sure. Should schools fear they are going to spread through schools and cause a citizen panic? No way.

Cockroaches are far more likely to migrate from a child's backpack and find "Southern Living" in a classroom. And backpack smuggling of cockroaches is at best a minor or occasional source of cockroach infestations in school classrooms.

Monday, November 24, 2008

Report from Reno

Five days and 27 pages of hand-scribbled notes later and I've returned from another Entomological Society of America annual conference. As usual, the meeting was an exhausting marathon of meetings and posters and mixers, sweetened by renewed personal contacts and much new and useful information about entomology and pest control.

Some of the sessions were probably topics only an entomologist would find fascinating, like measurements of insect diversity on Arizona mountaintops, how mosquitoes locate their hosts, or the history of DDT (which cost only $.18/ lb after WWII and even the famous Winston Churchill called "the miraculous powder"!). Nevertheless, there was much information that would be of great practical interest to a gathering of PMPs. Just a few valuable new insights and reports included:

  • An update was given on colony collapse disorder (CCD) of honey bees by Diana Cox Fisher, a researcher from Pennsylvania State University, who believes that a combination of stresses and new, or re-emerging, diseases (not pesticides) is probably responsible for the current crisis in bee deaths--at least in the U.S. Currently the best correlation with CCD seems to be a disease known as Israeli Acute Paralytic Virus, although the jury is still out on this one. She noted at the end of her presentation that one out of every three bites of food that we eat is thanks to pollinators like the honey bee.
  • Several interesting papers were presented on bed bugs. Mike Potter, of the University of KY, noted in his talk on the history of bed bugs, that within 5 years of the introduction of DDT, researcher John Osmun of Purdue University reported that it became nearly impossible for researchers to locate bed bug infestations to study. Tim McCoy, of Virginia Cooperative Extension, noted the importance and effectiveness of dusts as a tool in bed bug control. Tempo dust, Drione, and Tri-die dusts gave the fastest kill of all products (45 minutes to 6 hrs). Boric acid dust was the slowest, requiring over 18 days to kill. Dini Miller of Virginia Tech concluded that hydroprene was a useful additive to conventional sprays for bed bugs (especially resistant populations), though the effects of hydroprene are subtle and may not become evident until the second or third generation.
  • One of the most interesting bed bug talks was given by Changlu Wang of Purdue Climbup insect interceptor uses a rough outer surface to trap bedbugs in the smooth-sided inner 'moats'University. He compared spray-based and dust-based IPM programs for bed bugs. The liquid spray tested was chlorfenapyr, and the dust-based program used diatomaceous earth and an innovative bed bug interceptor device placed under bed posts to trap the varmits when they try to climb up, or down from the bed. The clever traps are being sold by Susan McKnight Inc. under the trade name Climbup™ Insect Interceptor. Both spray and dust-based programs worked well in Wang's tests. The traps caught more bed bugs than were observed by the inspectors in all apartments. Another interesting observation was that 94% of the trapped bed bugs were in the outer bowl, indicating that they were off the bed. This shows the importance of treating off-bed locations when controlling bed bugs. These devices might be especially useful for clients with low budgets and a high motivation to help with the elimination program. Of course the effectiveness of the bowls depends on eliminating contact of the bed and bedding with the floor and walls.
  • Tom Greene of the IPM Institute (organization running the Green Shield™ certification program for pest control businesses) reported results of a University of Florida study that showed that properly installed doorsweeps can reduce pest complaints in schools by up to 65%. He made an observation that I believe applies not just to school IPM programs, but to all professional IPM: "The question is not 'do you do IPM?', but 'how much IPM do you do?'" Most PMPs say they do IPM, but there is generally much room for improvement of the quality and depth of IPM done by professionals.

New Web Resource for West Nile Virus

dead blue jay sent in to be analysed for west Nile virusIn August I posted a story about the human face of West Nile virus. Now there is a website where people suffering from West Nile virus, or others interested in the disease, can exchange information about the topic.

It's called the West Nile Information Exchange, at, and it provides a forum for folks to talk about the disease and their experiences, or to learn more about research into WNV. The site was developed by Dr. Kristy Murray, an Assistant Professor of Epidemiology for the Center for Infectious Diseases and Associate Director for Research for the Center for Biosecurity and Public Health Preparedness at the University of Texas Health Science Center at Houston, School of Public Health. It has the option for visitors to register and read and post comments about WNV, and subscribe to the comments (like this site).

If you have an interest in WNV, have suffered from this disease or know someone who has, this might be a good place to check out. It's new, so new registrants can help get the discussions going.

Monday, November 10, 2008

Should PMPs kill BEEs?

It's time to put an end to oft-repeated story that bees cannot legally be killed.

Every spring I get calls from the public looking for someone who can help them get bees out of a yard or home. This is a valuable service that I wish more pest control companies would engage in. Because pest management professionals are frequently unwilling, or lack the proper equipment and knowledge, to do bee removal, the job often goes to folks in the beekeeping business who may or may not be licensed to do pest control. Smoke calms bees located in the wall of a home while they are treated with insecticide applied using an ultra-low volume sprayer.

I'd be a rich man if I had a nickel for pest control salesman that's told a potential customer they couldn't remove bees, because bees are protected. This story certainly sounds credible because most people see bees as beneficial. In addition, the media this past year has talked non-stop about an imminent collapse of honey bee populations due to a condition known as "colony collapse disorder" (CCD). The truth is that bees are neither tottering on the brink of destruction, nor are they protected by law.

There is currently no state or federal law stating that pest management professionals cannot kill bees that pose a threat to health or property. One possible source of this legend may be the warning statements on some pesticide labels that prohibit the use of insecticides on certain crops or flowering plants where bees might be actively foraging. These warnings are designed to protect wild or domesticated bees from colonies that do not pose an economic threat. Indeed these warnings help protect commercial beekeepers from losing bees and honey due to pesticide contamination.

Nevertheless, when bees enter a home to build their nest, it poses a stinging threat to the family, pets and neighbors, and it can eventually create additional household pest and odor problems. Old bee nests attract mice, cockroaches, dermestid beetle larvae, ants and moths to the wall of the home where the old comb lies rotting. Furthermore, all social wasps and bees defend their nests. And nowhere in Texas is immune to the threat of aggressive Africanized bees. Even the supposedly docile European honey bee also has quite a temper when conditions are right.

Using the definition of a pest as any organism where it's not wanted, honey bees can certainly be pests. And PMPs can certainly kill or remove honey bee nests anywhere they are not wanted.

But what about the demise of honey bees? If we kill them won't that hasten their almost certain extinction? No. In fact, wild honey bee populations are, by all appearances, quite virile--at least in Texas. To my knowledge, no one is currently tracking wild honey bee populations in our state, but I can detect no decline in the number of phone and email complaints about feral bee swarms and colonies in the past few years. Although Texas has been listed as a state with CCD, at last report the bee keeping industry here has not seen the precipitous declines reported from other states.

It's still unclear what is causing these declines in honey bees in the U.S. and abroad. There are numerous viable theories including new viral diseases, parasitic mites, stress from their high-maintenance lifestyles, and agricultural pesticides. But our Texas honey bees appear to be in no immediate danger.

As far as the ethical question about whether PMPs should kill bees or not, in my opinion this is more of a personal preference, with no one answer being right for everyone. As with anything, the decision involves trade offs: the benefits of reducing risks from stings and possible serious injury (even death) versus the decision to kill what is usually considered a beneficial insect. The economic cost of having to remove bee nests from walls, floors and ceilings of homes, versus the decision to destroy a swarm of bees sitting in the tree outside the window.

But why even talk about killing bees when they can (often) be removed alive? Live bee removal can be, and is, done by some companies, but not everyone has the expertise or the extra time to devote to live bee recovery and restoration. Simply, you can take them alive, but it will usually cost you more. Again, this becomes a personal decision on the part of the homeowner and the business owner.

Ultimately, the relatively few bee colonies that are exterminated from the walls and backyards of homes are not going to have much impact on the big picture of bee survival in Texas. So go out there and remove bees, and make money doing it. But if your company doesn't do bee removal just say so. Don't tell consumers that it's illegal.

Monday, October 27, 2008

The most influential commercials ever?

I grew up in the 1960's watching what are now considered vintage television commercials. I have vague memories of Winston cigarette and Maxwell House coffee commercials from the good old days, but one line of commercials remains permanently stamped in my mind. I remember bits of the old commercials for Raid insect killer as if I had seen them last week.

In those commercials the bugs were all evil villains bent on making life miserable for Helen housewife. But she always got her revenge. Typically the bugs ran into (what they think was) the safety of a wall or other nook, only to be followed by the Raid cloud of doom. They died violently screaming "RAID!" as the deadly cloud descended.

One of the great things about the Internet is the chance it gives us to recall these old trivial bits of our heritage. In this vintage footage from YouTube, the Johnson Wax folks sympathetically provide gravestones for the hoardes of dead bugs.

I'm pretty sure these commercials had a subtle but deep, psychological impact on a generation of Americans. I think we all cherish the notion that even if we can't stop war, or end racial strife, or even silence the neighbor's barking dog, at least we can control the creepy bugs that pester us. Perhaps that's the psychological power behind these old commercials. Whatever the reason, the psychology must have worked because Raid is still with us, and a new generation of updated commercials continues the genre (e.g., the Orkin man commercials).
This way of thinking, however, continues to create problems for those of us today who promote integrated pest management (IPM). To most Americans, pest control means "killing bugs dead" (the old Raid mantra). The idea that it might be more effective to modify the environment to make it less conducive to pests is, frankly, boring, and not nearly as entertaining as the fog of death.

In a twist of irony, the bugs appear to be winning at least one front in the bug bomb war. A recent report from the Centers for Disease Control looked at illnesses and injuries caused by TRFs (total release foggers) in eight states over six years (2001-2006). They found over 466 human injuries that appeared to be the result of overexposure to TRFs. Most (80%) of the incidents were considered low in severity, with 2% resulting in severe health impact or death.

The top causes for illness include inability or failure to vacate the premises before the TRF went off, coming back to the treated area too soon, unintentional discharge of the TRF, or setting off too many foggers at the same time. It seem that in many, or most cases, exposures occur because consumers don't follow label directions properly. The CDC notes in their recommendations that "IPM control strategies that prevent pests' access to food, water, and shelter need to be promoted and adopted. In addition, awareness of the hazards and proper use of TRFs need to be better communicated on TRF labels and in public media campaigns."

This is good advice, and something that pest control professionals should pass on to their customers. Doug VanGundy with Zoecon Corporation, a long-time manufacturer of less toxic pesticides (including some foggers) notes that TRF don't get nearly the kind of penetration into pest hideouts that the old Raid ads might suggest. "Today's water-based formulations don't produce the small particle sizes of earlier generation foggers," he said. "Although we believe foggers are still a viable product for consumers, professional application of insecticides via crack and crevice treatments and outdoor perimeter treatments to keep pests outdoors are probably best for most situations."
It's important to remember that foggers are designed principally for flying insects, or those on exposed surfaces. Fogging a home or apartment is just as likely to drive pests temporarily into harborages, or even cause them to spread to neighboring units. This would be especially true for cockroaches and bed bugs, who spend most of their time in cracks and crevices with little air exchange.

The old pesticide ads may be entertaining, but they're not good pest control. Foggers may have a place, but if you misuse them or expect them to solve all your insect problems the insects will be the last ones laughing.

Tuesday, October 21, 2008

Texas carpenter ants are lazy

My entomology career got its inauspicious start twenty-eight years ago when I interviewed for a pest control technician's job in Seattle, Washington. I knew I was interested in entomology at the time, had just graduated from college, and needed a job to help my wife go back to school. Little did I know how much of the next one and a half years of my life would be attending to carpenter ants.

Washington state, I learned, grows two things really well: slugs and carpenter ants. The slugs that fed on my garden tomatoes grew up to six inches long. The carpenter ants were everywhere. As I recall, about 75% of the accounts I carried as a residential pest control technician had something to do with carpenter ants. Carpenter ant damage is to Washington homes, about what termite damage is to Texas homes. I've since learned that the carpenter ant species plaguing Washingtonians is Campanotus modoc, the western black carpenter ant.

Since migrating south I've yet to see good evidence that Texas carpenter ants pose any significant threat to wooden structures. The worst damage I ever encountered was in my own home, where some carpenter ants had hollowed out some galleries in the foam insulation in a bathroom wall. On an athletic scale for carpenter ants, where C. modoc are the Superbowl champs, our wimpy Texas ants couldn't make it past the sofa with television remote and beer in hand.

The Texas carpenter ant community consists of different species than the one that pay the bills for Washington PMPs. Most Texas species have little interest in boring into solid wood, although they will nest in walls of buildings, and can be a nuisance. One difference is that colony sizes of carpenter ants in Texas are much smaller than C. modoc colonies, which may contain over 100,000 ants.

So a few weeks ago I was interested to receive this image from Jay Jorns, with JNJ Pest Control in Katy, Texas. It shows the contents of a Sentricon termite below-ground monitoring station (with sensor strip) that had apparently become home to a small colony of carpenter ants.

black carpenter ants in Sentricon termite monitorThe picture interested me because it shows the clean galleries typical of the structure-damaging carpenter ants of Washington and the eastern U.S., and because the station was checked regularly, it was unlikely that the ants had merely moved into termite-damaged wood. It was real wood damage, even if not from a home.

Jay sent me a follow-up sample of these ants, and they turned out to be the black carpenter ant, Campanotus pennsylvanicus. Although range maps show C. pennsylvanicus is found throughout all but the far western panhandle and far southern parts of Texas, it is not a common pest ant in the state, to my knowledge.

On the other hand, this carpenter ant is the principal structure-infesting ant in the east and upper midwestern parts of the U.S., where it is known to do structural damage. So why not so much a problem in Texas? I'm not sure. I'm hesitant to say that the black carpenter ant will never infest indoor homes in Texas, given their record in other parts of the country. But of all the carpenter ants in Texas, this species probably has the greatest potential for structural damage.

For anyone reading this blog, I am interested in seeing pictures of carpenter ant damage from anywhere in the U.S. Send me your images and I will post them online along with information about where the damage occurred (city, state) and your name (O fame!). Anyone from Texas who can show me bona fide carpenter ant damage to sound wood in a structure (not carpenter ants living in old termite galleries), I will send a copy of the very useful booklet, Ant Genera of Texas and praise you for your contribution to science on these pages. I look forward to hearing and learning from you.

Friday, October 10, 2008

Wanted: Buildings that build pests out

Anyone who's worked long enough in pest control has come up with bright ideas about how to do pest control better. It's called building a better mousetrap.

My current mousetrap idea is that we need to figure out how to get some of our brightest architects, engineers and code enforcement professionals to sit down together and come up with better ways to build a truly pest-proof building. Furthermore, if we were really smart, we'd market the ideas as part of the current green building movement.

And why not? Once you have a building that is either (1) very difficult for pests to get in, or (2) extremely uncomfortable for the pests that do get in, you should find yourself needing far fewer pesticides (cleaner air) and the cost of building maintenance should go down. Both clean air and reduced building maintenance costs are important to the goals of green design.

So why don't we do this? It's not because of a lack of ideas or know-how.

To pick just one pest challenge, we know a lot about ways to termite-proof a building. A quick Google search reveals, for example, that NCSU entomologist, Mike Waldvogel has a nice online guide to termite proofing a home. Building code experts have struggled with termite-proofing issues for years. The Florida Department of Agriculture and Consumer Services’ Bureau of Entomology and Pest Control has a publication about Florida's code requirements for new An example of termite-proofing, once the concrete is poured around them, these collars will prevent termites from entering the building through the foam insulating sleeves surrounding copper and PVC plumbing pipesconstruction to prevent termite damage. The National Institute of Building Sciences has an interesting website on a concept they call whole building design. This group secured government funding to develop a web portal on the concept, including information on termite proofing.

The concept should apply as well to all sorts of pests including rodents, cockroaches, a variety of crawling insects, birds, bats and other wildlife.

So why don't we do the things we know work well to save the consumer or business money, and reduce our need for pesticides? I think there are many reasons that pest proofing has not gained greater acceptance in the field of building design. For one, building a pest proof building is not as sexy or high profile as an avant-garde design, or a building with high energy efficiency or even one built using recycled materials.

Another important reason is that there is currently no good venues for pest management specialists and architects and engineers to sit down and talk with each another. Entomologists and pest management specialists traditionally have their meetings, and architects and engineers have their separate meetings. Rarely do paths cross.

Last February our office held a meeting with folks from around the country to discuss some of these issues. About 40 experts in pest management, architecture and engineering participated in a three-day seminar to share ideas on designing pest-proof public and commercial buildings. We discussed how integrated pest management concepts could be blended with green-building designs. Lots of good ideas were shared, but, unfortunately, comparatively few architects and engineers were able to participate.

We hope to try again next year at the 6th International Symposium on IPM, to be held in Portland, OR. If you know of anyone with a special interest in this area, you can tell me about it through the comment button on this post. I am especially interested in connecting with people who have expertise in building engineering, architecture and building codes. It can be a long process to build a better mousetrap, but it's one that's worth pursuing.

Wednesday, October 8, 2008

Go on a mosquito safari with new website

explore a virtual backyard by clicking on hidden hot-spots that lead to information about mosquitoesWhen it comes to mosquitoes disrupting the backyard barbecue, most of us want to point fingers. We want to blame the city for not spraying, or our neighbors for creating a nuisance. But a significant part of the time, we are our own worst enemies.

That's the subtle message of a new website I've just completed. But no one's pointing fingers, just pointing out the many place that mosquitoes breed and hide out in the average backyard.

The Mosquito Safari website will take you on a virtual tour of your backyard, encouraging you to see your property from the tiny perspective of a mosquito. Did you know that an old tire makes the perfect mosquito home? That garbage cans and garbage lids are one of the most common breeding sites for mosquitoes? What about bird feeders and bird houses in areas where West Nile virus is common--does attracting birds to your backyard make the risk worse?

These and many other questions will be answered as you take the time to explore this site. Topics covered include mosquito biology and life cycles, risks of mosquitoes to humans and pets, how to identify the most common mosquito pests, and the steps you can take to reduce mosquito bites in your own backyard.

If you visit, be sure to turn on the sound, as much of the site is narrated.

For pest management professionals, the site might be a good way to reinforce the messages your technicians are giving your customers about the things they can do to reduce their risks. New technicians? Mosquito Safari can provide at least a half hour of training time for trainees.

Of course a site like this is not developed by just one person. I want to acknowledge the Dallas County Health Department, and former entomologist there, Scott Sawlis, for invaluable help and guidance in design of the site. Dr. Mark Johnsen, mosquito expert with Texas AgriLife Extension in College Station, was also very helpful providing advice and support. One of my desires was to make the site visually interesting and graphical in all aspects, and for this I thank the number of people willing to contribute images of mosquitoes and mosquito-related topics.

Please check it out and let me know what you think.

The mortgage crisis and West Nile virus

mosquitoes like hot tubs tooJust when you think the news couldn't look any more bleak, we learn that home foreclosures are sparking a rise in cases of West Nile virus. Huh? Yes, the CDC's online publication Emerging Infectious Diseases will be publishing an article in November that provides convincing documentation that an increase in home foreclosures (and accompanying abandoned swimming pools) in Kern County, California has resulted in an increase in Culex mosquito breeding in suburban neighborhoods.

Kern County has been especially hard hit by the mortgage crisis, with the number of mortgage defaults increasing 300% from 2006 to 2007. During the same time the number of human West Nile virus cases there increased by 276%. Aerial surveys confirm the high number of abandoned or neglected pools, jacuzzis and hot tubs, as evidenced by their green algae-rich color. It's bad enough to live in a neighborhood of foreclosed homes, but it's worse when those backyard pools turn into mosquito factories.

Several species of mosquitoes, including the principle vectors of West Nile virus, thrive in fish-free water rich in algae and bacteria. In California, both Culex quinquefasciatus and Culex tarsalis larvae have been collected from pools. The situation is similar to what was seen after hurricane Katrina in New Orleans, with thousands of scummy pools in abandoned backyards after the storm.

The situation does not appear to be limited to California. According to an online article in even Senator Hillary Clinton has become aware of the issue. She recently asked the CDC to look into the possibility that the foreclosure crisis and vacant homes on Long Island, NY are leaving pools of stagnant water where the virus-carrying mosquitoes breed.

So what's all this got to do with the pest control industry? If your company does residential pest control, you should alert your technicians to the potential health threats posed by abandoned pools. Technicians should report abandoned or neglected pools to customer or the local health department. Health departments should be interested in contacting the owners of such sites as a potential public health nuisance.

If a dirty pool or jacuzzi belongs to a customer, and you have permission, temporary control of mosquitoes is possible by treating pools with Bacillus thuringiensis or methoprene-containing products labeled for mosquito control.

If your company is located in one of the hurricane zones in Texas, noting and reporting potential mosquito breeding sites is even more critical. And if you've been looking for a way to help out in your community, providing chemical or biological control of mosquitoes in backyards might be one of the most important things you could contribute to the re-building effort. If your company is doing something along these lines, let me know. I'd be honored to spread the word about your efforts.

Friday, October 3, 2008

New option for kids with fire ant allergies

red imported fire ant stings on a young handA recent story from Reuter's reports on a new, rapid treatment method to desensitize young children with severe allergic reactions to stings from fire ants. According to a study in the September 2008 issue of the Annals of Allergy, Asthma & Immunology, three children were successfully desensitized in a one-day "rush" protocol, consisting of 10 injections given over an 8-hour period.

Rush therapy is considered better than conventional desensitization therapy, because of the quick immunity it provides. This is especially important in areas where fire ants are common (endemic) because studies show that 38% of children aged 16 years or less are stung at least monthly by fire ants.

The study was the first to show the effectiveness of rush therapy on children. According to the authors, rush therapy has previously been shown to be effective on adults. However, this research provides evidence that young children, who are twice as likely as older children to experience allergic reactions to fire ant stings, may also benefit from this therapy. Results should be considered preliminary because of the small number of children tested.

One of the things I appreciate most about the profession of pest management is the health benefits we provide to individuals and the community. And let's not undervalue the benefit of educating customers about the latest in research and health impacts of pest. If you have a customer whose children have allergies to fire ants, consider informing them of the medical option of desensitization therapy. You might just make a difference in a family's health and peace of mind.

Saturday, September 27, 2008

IPM Thresholds: More than meets the eye

I've heard several pest management professionals say that they felt thresholds were not practical for their business. "We have a zero tolerance for pests," they typically say, "so thresholds just don't work for us." Health department standards are often cited as a justification for a zero threshold, as many health departments have no tolerance for cockroaches in a food handling establishment.

Developed originally for agriculture, pest thresholds originally meant the level of pest presence on a crop where the damage caused by the pest equaled the cost of treatment (usually the cost of a pesticide application). This concept works well in situations where the cost of a single pest is relatively easily determined. It's much more difficult to establish thresholds where pests are simply a nuisance or where the exact health cost of an individual pest is difficult to define.

The problem of assessing pest damage in indoor environments is especially challenging. What is the cost to a restaurant of a single cockroach in a kitchen? Contrary to the myth that a single cockroach is sufficient to shut down a kitchen, health inspectors, in Texas at least, are charged to "[control pests] to minimize their presence within the physical facility and its contents, and on the contiguous land or property under the control of the permit holder..." Nevertheless, we all know that there are levels of pests that are clearly unacceptable.

Most people would agree that a single cockroach, or one mouse, entering a facility from a recently delivered box of food does not necessarily constitute an "infestation". And one or two cockroaches on a sticky card would likely justify a much different (and less costly) response than, say, 30 cockroaches found on several sticky cards. This is where thresholds can help both the pest control technician and the food establishment manager.

I believe the most useful kind of threshold for these settings is what I call the multiple response threshold, where thresholds are used to guide the appropriate response to escalating pest densities. A good technician understands this concept intuitively, whether he or she realizes it or not.

This week I helped conduct a class on IPM for school maintenance personnel. As part of the class we conducted a pest inspection of a school kitchen. The technician who serviced the school told me he had recently found two cockroaches in a particular area of the kitchen we were inspecting. I asked him what he did, and he said that he conducted a thorough inspection of the area and found no other signs of cockroaches. He did not apply a pesticide, but planned to keep a close eye on this area in the next few visits. When asked what he would have done had he found more cockroaches, he answered that he would have increased sanitation, brought in a vacuum and perhaps placed out some cockroach bait stations.

This is, in my opinion, the proper use of the IPM threshold concept for buildings.

But if a good technician knows this intuitively, then why is it necessary to have written thresholds? There are several reasons I can think of for written thresholds, especially for institutional accounts such schools, restaurants or hospitals: (1) Not all technicians are equally experienced, or understand what to do when they encounter different levels of pest problem; (2) not all institutions or businesses have the same tolerances for pests. If they have been previously reviewed and approved by the customer, written thresholds provide a way to ensure that the technician is familiar with the expectations of each account; (3) technicians rarely keep the same accounts for extended periods of time, so having written thresholds is an excellent training tool and way to standardize service among technicians; (4) the process of developing thresholds is a useful exercise in thinking through your IPM service strategy; and (5) thresholds can save time and expense, especially for institutions where pest control service is based on a work order system. It can be expensive to send technicians out on trivial pest control service calls, when more important calls await. In this case, thresholds can help a manager decide which work order requests deserve immediate response, and which are given lower priority.

If your company does not include written thresholds as part of its commercial IPM program, it may be time to reconsider. Besides being a good idea, having thoughtful and reasonable thresholds might just distinguish your company from competitors who also claim to be doing IPM.

Friday, September 19, 2008

Fire ant baiting season winds down

fire ant face-up closeIf you and your company use baits as part of your fire ant control programs in Texas, or elsewhere in the south, now's the time to use up your bait for the year.

Fire ant baits are wonderful tools for controlling fire ants. They are low in toxicity to users, customers, pets, and even most other non-target ants. They are one of the most economical methods to control fire ants, and one of the most effective, consistently providing 90% or more control.

So what's not to like about baits? One of the few disadvantages of baits is that they are not equally effective throughout the year. Throughout the temperate areas of the southern U.S. fire ants stop searching for food (foraging) when soil temperatures drop below about 60 degrees F. If the ants stop foraging they will not pick up baits like Amdro Pro, Advion and Extinquish Plus. For this reason, baits should not be part of your winter fire ant program unless you work in south Texas or south Florida.

Venturing outside my office this afternoon, the soil temperature at 2 cm (a little less than 1 inch, the best measuring depth) was a comfortable 81 degrees F. This is well within the optimal soil temperatures for foraging of 72 and 97 degrees, so right now is still great weather for using fire ant baits--at least in the Dallas area. If you are unsure whether baits can still be used in your area, take soil temperatures at 1 inch during the morning and afternoon. If the average is between 72 and 97 degrees, you can probably still use baits.

Fire ant baits are best used when fresh, so any containers that have been opened within the past few months should be used soon. Fire ant baits have a relatively short shelf life once opened. Even unopened bait should be used within two years of manufacture. Because of this, buying large quantities of bait (perhaps because it's at a good price) is not necessarily a wise idea unless you are certain you can use the bait up during the season of purchase.

As temperatures drop over the next month or two, it will be best to limit your fire ant treatments to individual mounds, using labeled contact or residual insecticides. Winter is also a good time to apply broadcast treatments with granular fipronil (e.g., Top Choice), since it may take up to two months to see full control with this product during the fire ant season. Though more expensive and, ostensibly, not as "low-impact" as baits, granular fipronil provides good control for up to a year in most locfire ants often build mounds next to structures, leading to indoor infestationsations. It is also a good treatment to apply around the perimeters of structures to prevent colonies from settling close to a building where they might seek shelter during the winter.

Train your technicians to be generous when treating fire ant mounds with liquid insecticide mixtures. Research shows that best control with liquids is obtained when 1-2 gallons of liquid is used per mound. Avoid the use of granular or dust treatments of mounds in sensitive environments like schools or parks, since these products may remain on the soil surface for several days or weeks after application.

For more information about when and how to use fire ant baits, check out the fire ant website section on broadcast baits.

Tuesday, September 9, 2008

No such thing as an "ant"!

I'm convinced that training employees to document what they do is one of the most important, yet overlooked, aspects of technician training in pest control. If you're doing your work well, you want your work documented in the service tickets and logs and other paperwork you leave behind.

One of the best indicators of a well-trained technician is careful and descriptive recording of pest problems encountered during a service visit. One of the signs of a careless or poorly trained technician is sloppy notes.

A carpenter ant is not just an antI first noticed this a few years ago when serving as an expert in lawsuits involving fire ant stinging accidents in nursing homes. As part of the discovery process, it was my job to go through service tickets and note when and where fire ants had been noted by the pest control company.

To my dismay, I found that there was no way to distinguish what the technicians had been doing during their many visits to the locations I researched. Notations on the service logs and service tickets would typically read "treated for ants". Wait a minute. There's no such thing as just an 'ant'. What kind of ants? Pharaoh ants would require applying one of a few effective protein-based baits designed for pharaoh ants. Odorous house ants might require a sugar-based bait. For fire ants an outdoor treatment and inspection would be necessary, along with use of broadcast fire ant baits or outdoor mound treatments. Without good documentation, one has to assume that the technician didn't really know (or care) what he was doing.

We encounter the same problem when reviewing service tickets left behind in public schools. The past few years my colleague Janet Hurley and I have visited a number of public schools in various states to audit their IPM programs. In the process we've seen many service tickets left behind by pest control technicians documenting pesticide applications for "ants", "roaches", "flies", etc. As anyone who has worked in the industry can tell you, identifying a potential pest to ordinal level doesn't really tell you much. There's a world of difference, for example, between finding a dozen German cockroach nymphs and an American cockroach in a sticky card in a previously cockroach-free commercial kitchen. Think potentially dozens of service hours and repeated callbacks if the problem is not caught early. There's no such thing as just a "roach".

Flies are another great example of why identification skills and documentation are so important. Fly control is based on finding and eliminating the site where the larval stages of the flies are breeding. House flies in a kitchen? Check the outdoor dumpster and the back door. Fruit flies typically involve spilled syrups, rotten fruits or vegetables. Phorid flies may indicate a sewer problem. The customer may not know the difference, but the technician should. And the technician should communicate with the customer, a process that starts with the service ticket. There's no such thing a just a "fly".

Documenting pesticide use is another issue that I will undoubtedly revisit on another day. But today, just remember that when it comes to quality pest control, "there's no such thing as an 'ant'!"

Thursday, September 4, 2008

Nematodes for pest control?

A question came up today among an online extension fire ant community concerning the use of nematodes to control fire ants. Occasionally I hear from homeowners asking whether nematodes will work as a viable alternative to pesticides for flea, fire ant or white grub control in yards. I thought a little bit of background into nematodes (nemas, for short) might be of interest.

Nematodes make up their own phylum of organisms, the Nematoda, with over 80,000 species, according to Wikipedia. Though many species are plant feeders, a number of kinds are entomophagic, or insect eating and have potential for helping us control pests.

Unfortunately, putting a potentially beneficial organism to work for us is rarely as simple as we would hope. For this reason, if nematode control is ever to be widely used, it will have to be professionals that make it work.

Take grub control for instance. Control of white grubs in turfgrass is an area where nematodes can be successful. To learn more, Dr. Parwender Grewal, of Ohio State University provides useful recommendations for selecting an using nematodes against white grubs and other turf-infesting insects. Because nemas are living organisms, however, control procedures can be complicated. For this reason, I don't think we'll be seeing many do-it-yourselfers embracing use of nemas for yard insect control.

Professionals are much better equipped to provide this kind of service because of its very complexity. Pest management companies have access to microscopes to check viability of the nematodes prior to application. Also, professionals are able to develop the necessary skills and experience, and can establish and follow protocols that are necessary to get consistent control.

Fungus gnats are another pest that can be successfully control with nematodes. In a study by Harris, Oetting and Gardner in 1995, the nematode species Steinernema feltiae was just as effective as the insecticide diazinon in controlling fungus gnats. This approach is especially valuable in interior plantscapes where chemical use is undesirable and plants cannot be easily moved. Similar to using an insecticide, soil media is drenched with nema-containing solutions to prevent fungus gnat reproduction.

Unfortunately, fire ants have never been easily controlled with nematodes, due to their habits of grooming and ability to detect and evacuate sites where nematode populations are high. Dr. Robert Dunn at the University of Florida has developed a short fact sheet on this subject. According to Dr. Sanford Porter at the University of Florida, other more promising species of nematodes for fire ant control are being investigated. But right now the fire ants seem to be winning the nematode war.

What about other pests? Termites, like fire ants, are not easily controlled with biological control agents like nemas because of the difficulty in delivering predators and parasites to underground termite colonies. Also, flea control with nematodes is also not very promising at present. This approach has never been convincingly demonstrated in the field, as Dr. Dunn discusses in another fact sheet on flea control.

Tuesday, September 2, 2008

Playing without Pesticides?

In case you've not heard, there's a movement afoot to ban pesticides as part of a green approach to community improvement. Pesticide bans are most common in schools and parks, but are even being proposed (most famously in Toronto, Ontario) for whole cities. A recent news story from New Jersey tells of a school in Mansfield, NJ that has taken to posting "Pesticide Free" signs near the playgrounds to advertise the school's policy of not using pesticides (at least around playgrounds).

Such actions, in my opinion, are misguided and teach kids the wrong lessons. Those of you who love kids and the environment, like I do, please hear me out before you click the "close" button on your browsers.

Let's ask ourselves, what message do pesticide bans really convey? Let me propose a few.
  • All pesticides are bad for the environment. This message ignores the diversity of pesticide products, all of which are different in their modes of action and degrees of toxicity. A pesticide is, by definition, something that manages pests, not something that is dangerous for the environment. The environmental impacts of today's pesticides are significantly different than the products that Rachel Carson warned us about in the early 1960s. Few of today's pesticides, for one example, have the potential to accumulate in the food chain.

  • All pesticides are unhealthy for kids and the rest of us. Not true. The older, nerve-toxin targeted pesticides have undoubtedly contributed to this misconception; but there are lots of pesticides that pose very low risks to humans and non-targeted organisms.Over the past twenty years or so, especially, pesticide toxicity and persistence has decreased dramatically.

  • You can't trust science-based regulatory agencies to keep unsafe pesticides out of our communities. While I'm not ready to go to bat for all our federal regulatory agencies, few people fully appreciate the vetting process that U.S. pesticides go through before making it to market. Suffice it to say here that pesticides go through much more thorough and expensive safety testing than most other consumer-destined products.

  • We don't really need pesticides. This message denies the value that pesticides have historically provided in keeping food costs down (for the poor as well as the rest of our society), saving human lives by keeping disease-carrying pests at bay, improving safety and appearance of athletic fields (ask your kid's high school coach about this one), and maintaining healthy and comfortable environments for all of us (care to share your sleeping space with bed bugs anyone?).

Leonard Douglen, Executive Director of the New Jersey Pest Management Association, made a good point in a recent editorial when he observed, "When one considers the many insect pests that can attack children, from ticks that can cause Lyme disease to mosquitoes that transmit West Nile Fever, cockroaches that can spread a variety of diseases, as well as stinging insects, the need for professional pest control becomes self-evident."

One final observation. Pesticide bans may be more palatable to consumers, and seem more acheivable, in cooler, northern communities where outdoor pest problems are less common and less severe. In the southern states the warm season is longer, weeds grow faster, and insect and plant disease pressure is significantly greater than, say, Toronto. Under these conditions, pest management is more essential to maintaining safe and attractive landscapes. Try taking the average Texan's bag of fire ant bait away from him or her, and you'll quickly understand what I mean.

Legislators should be careful lest they think that pesticide bans are the way to go. I propose a more thoughtful and nuanced approach. It may not be as fashionable or simple a message as "Pesticide Free", but requiring use of integrated pest management, and making sure that pesticide applicators are well trained in the safe and judicious use of pesticides will, in the long run, be best for us and our environment.

Friday, August 29, 2008

Loss of a colleague

John JackmanCollege Station, TX. Yesterday the entomology department at Texas A&M University suffered a shocking loss with the unexpected death of Professor and Extension Entomologist, Dr. John Jackman.

John was a wonderful colleague with an encyclopedic knowledge of insects. For all the tough entomology questions (and there are lots of them) he was the go-to guy for me and my colleagues . Whenever there was a question I couldn't answer, I'd call John.

For the past 19 years since I've been here, John has been the department's principal responder to phone calls received from the public--no easy task. In addition, he was one of the first extension faculty to see and take advantage of the Internet's potential for public education. He built the departmental home page, the second most visited website in the Texas AgriLife Extension system. I've often wished I had half the computer knowledge he had.

In addition to his research on a wide variety of Texas insect and pest management issues, John was author and co-author, respectively, of A Field Guide to Spiders and Scorpions of Texas and A Field Guide to Common Texas Insects (Gulf Press Field Guide Series).

John loved the outdoors, and taught courses on aquatic entomology and, most recently, fly tying. The fly tying course was an innovative class that integrated concepts of aquatic biology with art and craftsmanship. It was offered through Texas A&M's entomology and art programs.

He was a long-time volunteer in the Boy Scouts of America, a dedicated husband and father to three sons. He leaves a hole that will never be filled.

Since 2003, I've been privileged to work with John and Extension colleague, Carlos Bogran, on the Texas Master Gardener Entomology Specialist program, an intensive, one-week course on entomology for Master Gardeners and Master Naturalist volunteers. To see images of John at work with the program, click here. Without John's leadership and initiative it never would have happened. John, we'll miss you greatly.

AgriLife Extension's AgNews this weekend posted a brief obituary of John with a link to the College Station Eagle's guest register where memorial notes can be posted online.

Monday, August 25, 2008

Swarming rover ants, Batman!

Rover ant swarmers are common now
Dallas, TX. If you've been getting higher numbers of calls than normal about swarming insects in customers' homes recently, the culprit may be rover ants.

Last month I posted an entry about two new ant pests for Texas, in which I discussed the true identity of a tiny rover ant that has been growing in importance throughout Texas. Since that post, the identity of the rover ant has been confirmed as the dark rover ant, Brachymyrmex patagonicus. This ant is believed to be a relatively new immigrant from South America, and is one of the latest in a string of exotic pests that seem to have found themselves a new home in the U.S.

The swarmers are similar in size to a Pharoah ant swarmer, about 3/16 inch (4 mm) long and brown in color. Like the workers, they have a 9-segmented antenna and single node (pedicel) between the thorax and gaster. This is the first year I have had so many ant swarmers submitted in mid-summer, and the most likely explanation seems to be the spread of this new ant.

Rover ant swarmers seem to emerge at night and hover weakly around lighted rooms. As with other ant swarmers, there is little that can be done to prevent the swarms, short of finding and sealing the small holes or cracks from which they emerge (an unlikely task). Fortunately, swarmer emergence is relatively short-lived, usually a few days to a week, and are at worst a minor nuisance. The worker ants can be more troublesome because of their persistence in returning to a variety of indoor sites.

Rover ants have been difficult for the industry to control. Janis Reed, of ABC Pest and Termite in Austin, presented her observations of the best control methods for this ant at the recent National Conference of Urban Entomology meetings in Tulsa, OK. She considers rover ants very difficult to control, and a pest for which there is yet no magic bullet.

Technicians at ABC Pest and Termite rely on a combination of baits and sprays. Standard ant sprays reportedly provide little, or inconsistent, control of these ants; however Reed reports that combination sprays, containing both a pyrethroid and a neonicotinoid insecticide (such as the new Transport Insecticide, containing both bifenthrin and acetamiprid), seem to provide improved control. Gel and liquid baits may provide temporary suppression, but continued inspections and baiting are needed to keep ants from returning.

Rover ants are honeydew feeders, often milking scale insects, aphids and other sap-feeding insects for their sweet secretions. Rover ants are even reported to feed off the secretions of subterranean aphids feeding on plant A good IPM approach, therefore, would be to treat nearby trees to eliminate sap feeding insects, in addition to using baits and barrier sprays on the outside of the building. This approach has a better chance of providing long-term ant suppression than either of these tactics used alone.

Monday, August 18, 2008

The bed bug challenge

bed bug nymph on human skin Dallas, TX. It's no secret that bed bugs are one of the biggest new challenges that the pest control industry has faced in many years. In some ways, as a pest control professional, bed bugs are your worst nightmare. Infested structures are mostly hotels and apartments, arguably two of the least profitable and most difficult kinds of accounts to service. Infestations are usually centered around beds and bedrooms, often the most cluttered and private rooms of a home. Good service is extremely time consuming and requires diligent follow-up to be successful.

On the other hand, bed bugs open up an opportunity for astute and detail-oriented companies. A company that can master bed bug control can easily open a growing niche in the pest control business. And there's no sign of bed bug problems slowing down or going away.

I'm not an expert on bed bug control. I'll leave that title to you guys who have a dozen or more jobs under your belt, and who have achieved a high level of customer satisfaction. But I'd like to share a few facts about bed bug control gleaned from the researchers:
  • Bed bug control is time consuming. In 2005, a survey of 225 pest control companies offering bed bug control services was conducted by Cornell University's Survey Research Institute (American Entomologist, Summer 2006). Most companies spent 30-60 minutes inspecting and preparing a typical bedroom and at least one hour to treat. This is not a fly-in, fly-out kind of job.
  • Count on multiple visits to get satisfactory control. In the Cornell study 62% of the companies claimed to control bed bugs in 2-3 visits. In a study conducted by Bayer Environmental Science, and reported by Byron Reid at last May's National Conference of Urban Entomology, U.S. pest control companies required 2.9 visits on average to control bed bugs.
  • Bed bugs provide one of the few legitimate times where baseboard treatment is justified.  Note the blood smears on the wall where residents crushed bed bugs.Lest you think lots of pesticide is required for bed bug control, the Bayer PMPs averaged only 3/4 gallon of liquid spray mix per apartment during the first visit, and approximately 1/4 gallon thereafter. The volume of sprays used should be relatively low, but the number of cracks and crevices treated is time consuming.
  • In the Bayer (manufacturer of Suspend) study, the number of callbacks were reduced from 3.45 to 1.75 when the PBO-containing product, Kicker®, was added to Suspend® sprays. Current data does suggest that pyrethroid insecticides might benefit from the addition of a synergist , like PBO. This is likely due to a relatively high incidence of resistance being found among bed bug populations in the U.S., as reported by Romero et al. in the Journal of Medical Entomology this spring (March 2007 , pp. 175-178).
To see more images of bed bugs and a bed bug treatment, visit my Flickr site here. Thanks to Carlos and Manuel Campos of C&M Pest Control in Dallas, for allowing me to tag along on a recent bed bug job.

Tuesday, August 12, 2008

Risks and pesticides

the pesticide label is a legally binding document
I was reading a new product label this morning and came across a phrase that caught my attention. The label stated that "It is impossible to eliminate all risks inherentlyassociated with the use of this product."

This phrase, undoubtedly drafted by a lawyer and--I suspect--ignored by most users of the product, reminded me of a profound principles of pesticide toxicology and safety testing--one that I think few of us fully understand or appreciate: "It's impossible to prove that a pesticide is absolutely safe."

Science is a wonderful process. It allows us to discover useful things about our world. It forms the basis for new technology, answers our deepest questions about the universe, and brings wonder into our lives. Science, however, has it's limits. One of its limits is that it cannot prove absence of harm with complete certainty. It's the old "you can't prove a negative" argument.

Let me give an example. If my job is to test the safety of a new pesticide, I may expose a variety of organisms to my product to see if anything bad happens. Toxicologists routinely do this in laboratories with mice and rats and bacteria. Some tests are designed to measure acute toxicity, others look for evidence of mutations, others for cancer or other chronic disease. Suppose in the course of my testing all the rats develop cancer. This would be alarming evidence that my pesticide might be a human carcinogen. Evidence is strengthened if there are epidemiological studies that show a pattern of elevated cancer rates in humans exposed to the pesticide during its manufacture or use.

Now suppose there are no signs of cancer or other illness in my animals. Have I proved that my pesticide is safe? No. Science, because of physical and economic limitations, cannot prove safety with absolute certainty. For example, pesticide toxicology studies are not generally performed on people for ethical reasons. And people, despite our many occasional similarities, are not rats. Also, we cannot rule out all possible genetic, environmental or health factors that might influence carcinogenicity.

We know of cases, for example, where pesticides have proved exceptionally toxic to people taking certain prescription drugs. In these cases the drugs interfered with the user's ability to detoxify the pesticides, making them more toxic.

If we insisted that science provide absolute proof of safety, the science would become almost infinitely expensive. The best we can do is require a robust set of testing requirements, and base our decisions on the best available science. In addition, there should be a system of reporting suspicious patterns of health complaints associated with pesticide manufacture and use.

This is exactly what we do in the United States. The U.S. has, arguably, one of the best pesticide registration and approval processes in the world. New pesticides are incredibly expensive to register, in large part because of the safety testing required by the U.S. Environmental Protection Agency. The biggest beneficiaries of this regulatory process are those of us who work with pesticides on a daily basis.

So what's a pesticide applicator to do? Follow the label. The answer is so obvious that we often forget to do it. Labels are written to provide wise protection from the admitted limitations of our science when it comes to safety testing. From the precautionary statements, to the requirements for protective clothing, pesticide labels provide uncertainty protection.

Though they can be extremely uncomfortable in heat (especially in our part of the country), gloves, respirators and chemical resistant clothing, when required on the label, are essential to our safety. It may be necessary to explain this to a customer who balks at an applicator wearing gloves or breathing filters. They can be told that the extra protection is required by law (the label is the law) because, unlike them, applicators are exposed on a daily basis to our pesticide tools. It's not an admission of toxicity; it's a common sense precaution. It's an acknowledgement that we don't take unecessary chances with ours or our customer's health.

We should remember that there will always be risks working with pesticides, as with nearly any other consumer chemical product. That's the surprisingly wise message of the pesticide label.

Wednesday, August 6, 2008

The human face of West Nile virus

Dr. Don Read leads the Dallas support group for West Nile virus survivors.Dallas, TX. We hear of rare illnesses and diseases nearly every day in the newspaper or on television. After a while, I think most of us become a little jaded, and tend to forget or ignore threats that have not affected us personally. One of these relatively obscure diseases is a mosquito-borne illness called West Nile virus. Since 2002 Dallas county has averaged 45 clinical cases and two deaths a year.

These numbers may not seem like much...on paper. But these are real people who contract mosquito-borne disease every year. They include our neighbors. Friends. Parents. Teachers. The tiny bite of a Culex mosquito can, if infrequently, lead to a life-changing illness. Many of us reading this post may have already been infected by this virus. Only 20% of infected persons show any signs of the disease, and most of those will have little more than the sniffles. One in 150 infected persons, however, will contract the more serious central nervous system form of the disease.

Despite my awareness of West Nile virus and the clinical implications of the disease, until I met actual victims I don't think I really appreciated the power of this virus to potentially affect my life or the lives of loved ones.

Dr. Don Read and his wife Roberta lead a support group for victims of West Nile virus in the Dallas area. There are only a handful of such groups in the country, but they can be a godsend for people who have suffered from one of the more serious cases of infection. Last week I had the chance to attend one of their support group meetings at Medical City Dallas Hospital. It was a sobering experience to listen as people shared their encounters with the disease.

This month's meeting was covered by Reporter Melissa Maynarich from Oklahoma City's CBS Channel 9 News. She and her photographer posted a video story of some of the folks at this meeting. If you are interested in the human side of the West Nile virus story, check it out at

It might make you look at mosquitoes a little differently. I know I'm reaching for the repellent more these days. If you know of someone who has suffered from West Nile virus, or just to learn more about the disease and the support group in Dallas, check out the Dallas County Health Department's website on West Nile virus.

Tuesday, August 5, 2008

Demands for mosquito control likely to rise

It seems Hurricane Dolly brought with her more than rain. Following the record rains and flooding mosquitoes have also arrived by the semi-truck load.

Mosquito pressure is often measures in terms of numbers of landing rate per minute. A volunteer will expose a leg and another person will count the number of mosquitoes that alight on the exposed skin for one minute. A recent Harlingen survey put the average per minute landing rate at 120, with a high in one location of 384 mosquitoes per minute! Aedes vexans floodwater mosquitoes are painful biters That's a lot of mosquitoes.

A regional spraying effort started this week in south Texas. Airplanes will be applying the insecticide Dibrom to most parts of the lower Rio Grande valley to suppress numbers of especially floodwater mosquitoes that are the first species to come out after a flooding event. For more information about the spray program, see the August 2 article in the Rio Grande Guardian.

The ironic thing about these efforts is that floodwater mosquitoes pose a relatively low threat for arthropod-carried viruses, such as encephalitis and West Nile virus. The mosquitoes that carry these disease pathogens typically come out once waters begin to subside and leave numerous pools of stagnant, standing water. Not to say that spray efforts will not be without effect. Population numbers of the levels described for Harlingen would leave anyone miserable and crying for relief.

Once the huge numbers subside, and the spray planes return to their bases, the pest control industry will have an important role to play in helping reduce the risk of bites and disease. Experienced PMPs can point out to people areas where disease-carrying mosquitoes breed in their own backyards. In addition, the use of residual insecticides applied carefully to mosquito resting places in backyards and surrounding trees can significantly lower mosquito biting rates.

In one study conducted in Kentucky, and reported in the May, 2005 and October, 2006 issues of PCT magazine, backpack mistblower sprayers provided up to 6 weeks suppression of mosquitoes in backyards. Such treatments provide a valuable service to residential customers and can even reduce the risk of mosquito-borne disease by reducing populations of Culex mosquitoes, the primary vector of WNV and the various encephalitis diseases.

With today's landing of tropical storm Edouard, mosquito control will be an important issue for the pest control industry in Texas for the next two months. If you own a business in one of the areas affected by storms this summer, you owe it to yourself and your customers to read the research updates in PCT magazine, linked above.