Thursday, September 20, 2018

On alert for armyworms

Fall armyworm caterpillars feed mostly on grasses. This year
is proving to be a banner year for armyworms in some areas.
Pest management professionals who care for lawns should be on the alert for fall armyworms this fall. Higher-than-normal populations of this lawn-eating insect have been reported from many areas in Texas these past two weeks.

While fall armyworms are nothing new, according to Dr. Allen Knutson, extension agricultural entomologist in Dallas, this year they are a widespread problem for hay producers and small grains producers across the state.  "I've had calls as far west as Wichita Falls, south to Comanche and across east Texas," he said.  Locally in the Dallas/Fort Worth area, my turfgrass colleague, Dr. Lindsey Hoffman, and I have gotten many calls this week from concerned lawn owners, schools and the media.

Fall armyworm (FAW) is the caterpillar stage of a drab gray moth, known scientifically as Spodoptera frugiperda. It feeds primarily on grasses, though it has been reported feeding on dozens of non-grass plants and weeds. It earns the name "armyworm" from its habit, during times of major outbreaks, of marching, army-like, across fields and roads and yards, consuming everything in its path.

Identification

Fall armyworms blend in well with the grass and soil. Careful
observation of the grass and bare areas may be needed to confirm
fall armyworm presence.
The FAW caterpillar is identified by three thin white or yellow stripes on the shield behind the head (pronotum), an inverted white Y on the face between the eyes, and by four dark hair-bearing bumps (tubercles) on the top of the 8th abdominal segment.  It takes three to four weeks of feeding to reach its full length of about 1.25 inches (34 mm). For a video that will help you recognize FAW in the field, click here.

The adult FAW moth has a wingspan of about 1.5 in. The hind wings are white; the front wings are dark gray, mottled with lighter and darker splotches. On male moths each forewing has a noticeable whitish spot near the extreme tip.

Damage and Control

Damage often appears to occur overnight, though armyworms need at least three to four weeks to complete their six larval stages (instars). The last week or two of the larval stage is when most of the feeding, and damage, occurs.

Fall armyworms feed on most common lawn grasses like bermudagrass and St. Augustinegrass. But because armyworms feed on the leaves, and not on the critical roots and stolons, a little irrigation or a rain should restore lawns to their original condition within a week or two.

If this is unacceptable to your customer, FAW is relatively easy to control with any pyrethroid insecticide.  Organic customer lawns can be treated with products containing spinosad, a naturally occurring microbial toxin.  Be sure to avoid treating areas with flowering weeds or clovers that might attract bees, or else mow the lawn (and flowerheads) prior to treating.  This will help protect pollinators that might otherwise be attracted to freshly sprayed lawns.

Fall armyworm adult are strong fliers, travelling hundreds of miles from overwintering sites in south Florida, south Texas and Mexico each spring. In an strange, apparent case of migrational suicide, offspring of these northern migrants cannot survive freezing winter weather.  And unlike monarch butterflies which return to Mexico each winter, FAWs never return south. Therefore, they and all their offspring perish in the cold weather. The evolutionary advantage of this unusual behavior, if any, is not well understood.

For more information on our Aggie Turf website, click here.



Friday, September 7, 2018

Cixiid planthoppers

Here's one you never learned in technician training. Cixiid planthoppers are 1/4 inch-long (5 mm-long bodies) insects that are common at times on trees and shrubs. They are plant feeders, with nymphs that feed underground on grass roots. They are not your typical household pest.
Cixiid planthoppers are occasional invaders of homes,
identified by their jumping legs, finely veined, overlapping
wings. Note the dark patch (stigma) on the leading edge of
the forewing. Body length 5 mm, with wings 8 mm.

Over the past week in Dallas, however, I received numerous calls about these insects. One family described themselves as being "tormented" by these bugs, that insecticides wouldn't kill them and that the "bites" they were experiencing were surely these bugs.

The truth is, cixiid (sicks EE id) planthoppers do not bite and are harmless to people. Also, their damage to plants is negligible. Their only crime is that they are sometimes attracted to lights at night and, consequently, occasionally invade homes. Apart from reducing outdoor lighting and sealing windows and vents (especially next to outdoor lights), there is no real control for these creatures.

Infestations of cixiids should be temporary, but they are an interesting example of how, even in urban areas, nature occasionally intrudes on our otherwise sterile lives. They are also a good example of why the more a PMP knows about all insects (not just pests), the better professional he or she will be.


Friday, August 31, 2018

Watch this bug

This picture of BMSB was taken in Dallas
County
 in 2017 by Annika Linkqvist and
posted on iNaturalist. Note the white bands on
the antennae.
Brown marmorated stink bug has been causing a stink, literally, in many parts of the country for the past 15 years or so. It feeds on important crops, and finishes up its dirty work by invading homes in the fall.  It's the complete pest. Bad for farmers and homeowners alike.

Now the BMSB may be making a new home in Texas. According to EDDMaps distribution records, this stink bug has now been confirmed in four Texas counties. Two sightings were recorded last summer in Dallas County by the same observer, and one in Collin County in 2015.  It has also been seen in Harris and Ft. Bend counties in the Houston area.  To our knowledge there have been no reports of buildings being invaded or plant damage.

I live in Collin County and have yet to see a BMSB; but that doesn't mean they're not here, slowly reproducing and hiding out until they make their grand entrance. When they do, chances are that a pest control company will be the first to know.

I first posted about this pest 7 years ago, before any sightings in the Houston or Dallas area. Given these recent reports, I think its time to renew the call to vigilance.

Identification

So how do you identify BMSB? First, it is a stink bug (family Pentatomidae), all of which have flattened, shield-like bodies with a triangular plate in the middle separating the bases of the two wings. The BMSB is brown, about 17 mm-long (2/3 inch), and may produce a musty scent when disturbed. Several other stinkbugs look similar to BMSB. Identify by looking for three characters: First is the white band at the joint between the 3rd and 4th (last) antennal segments (see image).  Second is the shoulders: the BMSB also has rounded shoulder angles (corners of the pronotum at the widest part of the body) compared to other stink bugs with pointed shoulder angles or jagged teeth above the shoulder. Last, there are four creamy spots on the pronotum (shield) just behind the head and on the top of the scutellum (triangular shaped plate between the bases of the wings).


The brown marmorated stink bug (Halyomorpha halys, right) can be distinguished from the brown (Euschistus servus, left) and bark (Brochymena quadripustulata, center) stink bugs by markings and the white bands at the joints of the antennae.  (Note: These images not necessarily to scale.  The two left photos were taken by Mike Quinn, TexasEnto.net; and the right image by Melinda Fawver.  Thanks for permission to use.)

What to do

If you think you've run into an infestation of brown marmorated stink bugs, let me or one of our extension entomologists from around the state know.  To confirm, we will need specimens or good quality digital images.  If you choose to send a specimen, please follow the directions on this page, and include a completed insect ID form with accurate information about date and location where the specimen was collected.

We are especially interested if the bugs are damaging fruit (fruit, corn, grapes, tomatoes, beans) or coming to lights and invading homes in large numbers. If you have a good picture and want to report an infestation, you can also report to our national EDDMaps database at http://www.eddmaps.org/bmsb/report/.

This insect has the potential to become a major headache for households and businesses, as well as farmers. It reminds me of my latest proverb: "If you crave job security in your career, go into highway construction or pest control." Just as there will always be highways being repaired, there will always be new pests to battle. Brown marmorated stink bug is a good example.

Thursday, August 9, 2018

Bugs and basil: Insecticides and veggies don't always mix

Who wants to eat insecticide?  Not me, and I'm guessing certainly not your customers.

So if your company does residential pest control, are your employees trained to know what to do when they encounter a vegetable garden, fruit or nut tree in a backyard?  And are they trained to answer a customer's questions about the safety of their insecticides around vegetables or herbs?  

Do your employees know what to do when encountering vegetables, herbs 
or other food plants around a home? Asking a customer about their edible
plants might save that account. Photo by Jeff Raska.
 
I'm guessing this subject is not commonly addressed in technician training classes. I was asked by an industry sales representative this week: "Is it appropriate for a technician to be recommending that a homeowner simply wash their vegetables after having their yard treated for mosquitoes, or should the vegetables should be thrown away?"

The answer to this question depends on whether the plants were directly exposed to the spray and what the label says.

I did a quick review of the common mosquito adulticides used in backpack sprayers.  None of them allow application to edible plants.  The Suspend® Polyzone label, for example, says “do not apply this product to edible crops.” The Fendona® label says to not use on vegetable gardens.  Some make no mention of vegetables or edible crops at all.  And when it comes to edible plants, if application is not explicitly mentioned, it's not allowed.

Will pesticides make a plant toxic?

Of course many insecticides, including some of the active ingredients in your tool kit, are used legally on crops all the time by farmers. This is allowed by the EPA only if that pesticide has been granted a tolerance for a given crop, and certain days-to-harvest intervals are followed.  These rules work to ensure that any pesticide residues left after a pesticide application are below levels of concern for human health. The 2016 Pesticide Data Program survey by USDA shows that this system works. Out of 10,000 market food samples analyzed in the study, over 99 percent had residues well below the EPA established tolerances. More than 23 percent had no detectable pesticide residue.

So insecticide residues on plants are not necessarily toxic, especially when label directions are followed and adequate time passes to allow the product to naturally degrade. The products we use in pest control may be the same active ingredients used by farmers; but they may differ in concentration and formulation. Most importantly, pest control insecticides do not carry food-treatment labels so they cannot legally be used on edible crops.

Talstar® products, for example, consist of the active ingredient bifenthrin, the same active ingredient used by farmers and even home gardeners under a variety of trade names. The Talstar® P label for mosquito control, however, says "not to apply to bearing fruit or nut trees or vegetables or edible crops." To a law judge it won't matter whether other formulations allow application to food crops. To a judge enforcing FIFRA requirements, you must follow the label on the product you are using.

Spray contamination 

If an insecticide is deliberately sprayed on an edible crop or plant, and the product is not labeled for such use, the plant would not considered safe by EPA standards. The implication is that all of the plant, or at least the edible parts, should be thrown away. Your customer could replant, of course, unless prohibited by the label.

Backpack mistblowers are commonly used
for applying residual insecticides to mosquito
resting sites; but mists should be applied carefully
to avoid drift onto fruit and nut trees and
vegetable gardens.
Labels generally do not, however, prohibit use of these products in the vicinity of a vegetable garden. I assume this means that if you take care to keep sprays directed away from vegetable gardens, any incidental drift from nearby spraying with a coarse spray, aerosol or mist generator equipment should not be a problem. Likewise, thermal foggers and ULV applications used nearby should leave insignificant residues as long as the application orifices are directed away from edible plants at all times.

Of course applicators should always be aware of weather conditions and the locations of edible plants.  If wind is blowing toward a garden, upwind applications should be avoided.

So what should you do if a fruit, nut, vegetable or herb is is accidentally over-sprayed? Such a plant should be pulled, or else the produce should be left uneaten or discarded, by the customer.

Systemic insecticides

Some insecticides are "systemic," meaning they have enough water solubility to be taken up by plant roots and translocated to other parts of the plant. Although the EPA allows some systemic insecticides on crops, in general systemics are not labeled for use on food crops because they can leave residues in edible plant tissues that do not quickly degrade.

Insecticides containing neonicotinoids and acephate are examples of PMP insecticides that may be systemic in plants. These include products like Merit®, Premise®, Transport®, Tandem®, Alpine®, Temprid®, Orthene® and others.  Herbs and other root or leafy vegetables exposed to systemic insecticides should be considered contaminated for the season and should not be consumed.

Some termiticides can also be systemic in plants, leading to concerns about vegetable gardens planted next to homes treated for termites. Fipronil, for example, is slightly systemic in some plants; and the Termidor® SC label says not to "apply around edible plants."  The label does not say explicitly how far away an edible plant must be, although the Premise® 2 label (whose active ingredient, imidacloprid, is much more water soluble) is more specific. It says to "not treat within a distance of one foot out from the drip line of edible plants."  The Premise® guideline, therefore, is probably a good, conservative guidelines for all termiticides. Keep the outermost leaves of garden plants at least a foot away from any soil-applied termiticide and you should be OK.

Washing

Regarding washing, your technician may want to suggest vegetable washing to a concerned customer whose nearby yard or house perimeter has been treated with an insecticide spray.  Washing is a good idea whether pesticides have been used or not. The best washing technique includes a pre-rinse with a 10% vinegar solution (for germ control) followed by 30 seconds of tap water.  This is a great way to remove urban dust, microorganisms and traces of pesticides from vegetable and fruit surfaces.  

Would you recognize an edible plant?

Lastly, can you and your technicians tell a basil from a begonia, a mint from a marigold, or a pear from a poplar? Any applicator wanting to follow label directions around a home needs to be aware of what plants are present. We all don't have to be botanists, or know all the local tree species; but we should recognize the most common fruit and nut trees, herbs, and vegetables. Would you know what the common herbs sage, basil or rosemary look like? Sounds like a good exercise for training day.

When visiting a residence the first time, ask your customer if they have any herbs, fruit trees, nut trees or vegetables that you need to be aware of. Today's gardeners are more likely to plant edible plants within flower gardens, so you might have a basil plant or a tomato plant growing among the daisies. Assume your customers are organic in their vegetable garden and avoid these areas accordingly.

Believe me, your customers will appreciate any extra consideration you give to their home gardens. Treat them well and they might even greet you at the door with a big bag of zucchini.




Tuesday, July 24, 2018

Keeping up with mosquitoes

Every knowledgeable PMP knows that assessment and monitoring is a crucial part of integrated pest management (IPM). Yet practically no one in the mosquito control business monitors mosquitoes. Why is that?

BG Sentinel traps are among the most popular
traps for sampling nuisance biting mosquitoes
like Asian tiger and yellow fever mosquitoes.
Well, mosquito surveillance isn't easy. It's time consuming, requires expensive sampling equipment and specially trained personnel.  Disease surveillance means sending mosquitoes to an outside laboratory or else conducting expensive, highly technical lab tests. So, it's no surprise, really, that few pest control companies include monitoring services, beyond perhaps backyard inspections for breeding sites.

Yet, monitoring remains important to any PMP wanting to implement an IPM/IMM program.  Without monitoring you don't know what mosquitoes are biting, what diseases are circulating, and when human risk is highest.  So what's a mosquito technician to do?

Good news. Many counties, mosquito abatement districts and cities have area-wide mosquito surveillance programs.  While not necessarily focused on your customer's property, these area-wide programs are often quite good. Some even provide neighbor-hood level detail in their public reports.  They may chart Aedes mosquito numbers collected from traps like the carbon dioxide-baited BG Sentinel trap.  And they may provide both Culex mosquito numbers and disease prevalence from gravid traps.

The gravid trap is an especially powerful monitoring tool.  West Nile carrying Culex mosquitoes are drawn to these traps like cats to catnip. They are typically baited with polluted water known as "stink water." While every health department has their own formula for stink water, it's usually made by steeping grass clippings in water for 2 weeks or so.  The foul smell of the water draws gravid female mosquitoes as they seek stagnant water for egg laying.  Gravid traps help health departments measure the number of potential WNV-carrying mosquitoes present.  Mosquitoes collected in these traps are also collected into groups, or "pools," and sent to laboratories for virus testing. Some health departments publish this data in up-to-the-week reports that can tell you and your customer about their local, seasonal risk for West Nile and related viruses.

Gravid traps consist of a tray with "stink water," with a suction
trap positioned a few inches above the water. Female mosquitoes
drawn to the water for egg-laying are sucked into the trap, where
they are collected, counted and prepared for testing.
If you live in or near one of these health departments you should be able to get useful information about your community's mosquito status by visiting their website. Some health departments even provide weekly email updates on West Nile virus and Zika surveillance. Usually all you have to do is ask to subscribe to these reports.  For those of you in north Texas, the Dallas County Health and Human Services (DCHHS) and Tarrant County Public Health departments offer some of the best mosquito epidemiology reports I've seen.  To see a sample report, click here.

There's a lot of data in these reports, but some of the key things I look for include the following.  Where in my community has WNV been detected in mosquitoes? How abundant are Aedes mosquitoes (these are the daytime biting mosquitoes most noticed by your customers)? How abundant are Culex mosquitoes (responsible for transmitting WNV to people)?  And how is the Vector Index changing?

A July 2018 graph from Dallas County Health and Human Services shows the average abundance of West Nile virus
(WNV) mosquitoes, and a calculated Vector Index (V.I.) in both 2012 and to date in 2018.  A V.I. greater than 0.5
indicates high risk of a WNV epidemic, and may serve as a threshold for aerial spraying against mosquitoes. 
The blue dotted line is the V.I. from 2012, the year of the most severe WNV outbreak in Dallas with over
400 cases and 20 deaths. This year's data (in red) shows high mosquito abundance, equivalent to 2012,
but a relatively low V.I. suggesting that human risk from WNV is still relatively low.  Graphs like these
provide a weekly snapshot of public health risk due to mosquito-borne disease.
The Vector Index (V.I.) is a mathematically calculated number that combines information about both mosquito abundance and percent of mosquitoes carrying the West Nile virus.  If numbers of mosquitoes are high, but disease incidence is low, the V.I. will show low risk.  If mosquito numbers and disease incidence are high, the V.I. will be high.  The DCHHS considers a V.I. of 0.5 or higher to constitute an unacceptable high risk of mosquitoes. For Dallas county a high V.I. will trigger emergency public health measures, possibly including aerial spraying of insecticides.

Most of your customers will likely not be familiar with health department data, nor will they understand its interpretation. But by taking the time to get access to the data, and understanding its significance, your company can serve as an educational bridge to your community. By letting customers know when disease incidence and mosquito abundance is highest, everyone is reminded of when to take special steps to avoid mosquito contact, and the importance of their own mosquito control.

It's often said that information is power. Whether you include residential mosquito control as a special service, or simply an add-on benefit to your regular customers, you owe it to them to be informed about what mosquitoes are doing in your community.  A call to your local health department can provide you with a wealth of public health data, that can make you more a powerful advocate for your clients.

Some Texas and national WNV and mosquito information can be accessed online at:






Monday, June 25, 2018

Moving Beyond Mallis: The Veterans' Perspective

If you work in the pest control industry, and are even a little geeky about insects, you would probably like the National Conference of Urban Entomology.  Held May 21-23 this year in Raleigh, NC, the NCUE is the premier gathering for research and industry experts in structural pest control.  This year had more than its share of nerdy bug news.

In my last report I shared research papers presented by students. In this segment I will highlight talks given by “veteran” researchers, some of whom you may know by reputation or from state or national CEU conferences.

One of the most stimulating sessions this year focused on a term that was new to me: “assessment-based pest management.” Dini Miller from Virginia Tech thinks it might be the next big thing to replace (or improve) integrated pest management (IPM), a central philosophy of urban pest control.  Miller argued that because the IPM concept comes originally from agriculture, its logic has never resonated deeply with the public. Few people seem to associate the term “integrated,” for example, with the idea that using multiple pest control tactics (integrated controls) are safer and more effective than the "one spray to kill them all" approach. 

Assessment-based bed bug control will come if class action
lawsuits over failed control continue. Studies continue to show
that complaint-based service contracts do not solve bed bug
infestations. Pitfall traps, like this, can be used to detect bed
bugs early when control is more easily achieved.
Talking about assessment as a basis for pest control, she argues, might be an easier sell.  After all, all big companies assess their success by looking at the bottom line. Athletes assess their success with their batting averages and quarterback ratings. Investors follow financial assessments of their investments through annual reports. Shouldn’t consumers intuitively understand that assessment-based pest management is in their best interests?  Maybe.

But how would an assessment-based pest management program work? Without offering a comprehensive answer, speakers at the “assessment” session highlighted better ways to use monitoring and measurement in pest control.  Miller showed, for example, how by pre-assessing cockroach infestations in an apartment as low, medium or high, she could meter out how much bait a technician would need to get excellent control in that unit.

Rick Cooper, of Bed Bug Central, is successfully controlling bed bugs in low income, high rise housing—one of the toughest accounts for pest control. “Early detection is key,” says Cooper, who finds pitfall monitoring traps the most consistent way to detect bed bug infestations, even better than canines. Cooper assesses the success of his management efforts by looking at two metrics: percent of apartments with detected bed bugs, and severity of infestations based on numbers of bed bugs caught in traps. In one study he used an assessment-based approach, in combination with simple, non-chemical and low-impact control measures, to treat all apartments detected with bed bugs.  Using an in-house pest control company, they were able to reduce infestation rates from 15% to 2% over 12 months, while achieving a 98% reduction in bed bug counts. Given the success of class action suits against apartment management in recent years, it’s hard to see why managers would NOT demand this kind of information from their pest control providers.

Assessment based classes show the value of hands-on training
to teach both novice and experienced pest control professionals.
Faith Oi teaches at the University of Florida's Pest
Management University.
Faith Oi, University of Florida, focused her talk on assessing the effectiveness of continuing education through the Pest Management University (PMU) classes she offers. For any company wanting to recruit and maintain a well-educated workforce, Oi argues that training is key, including training for supervisors. Oi used pre- and post-tests to evaluate learning at PMU. For 330 students tested, she found an average 58% increase in test scores regardless of how long someone had worked in pest control. Surprisingly, supervisor pre-test scores were not significantly higher than technician pre-test scores.  Hands-on training, and training materials that are understandable to today’s technicians and even supervisors are critical. With a jab at EPA labels she observed that although pesticide labels are not infographics, perhaps they should be. What a great idea!

Michael Scharf, Purdue University, took assessment in a different direction. Imagine if, at the time of selling a big cockroach job, your company routinely collected cockroaches from the site, put a few in special, treated vials, and knew the next day precisely what insecticides would and wouldn’t work at that location? That’s what Scharf is pioneering. In a field trial he was able to predict ahead of time which insecticide combinations would work (some of his cockroaches were resistant to neonicotinoids and some were resistant to pyrethroids).  In a few years you might be able to purchase a set of pre-treated vials with instructions telling you how to run a resistance detection test. This could be a game-changer, because resistance can vary from one apartment complex to another—even within the same city or neighborhood.

To be effective, however, assessment must be affordable. Karen Vail, of the University of Tennessee, looked for a fast, cheap and effective inspection protocol for detecting bed bugs. First, she investigated whether residents, management and maintenance staff, and pest control professionals could be trained to work together to take over maintaining and inspecting pitfall traps. But after training these groups to find, report and clean traps, only 10% of apartments had maintained their traps (in place and dust free) after 22 months. She then tried a quick visual inspection of all apartments, followed by placing 2-8 traps only in apartments with a complaint or some evidence of bed bugs.  With as few as 2 traps per apartment (one against the foot of bed and one against a living room chair) she was able to detect 80-90% of the infested apartments in 3-4 weeks. It took only 2-3 minutes to conduct a quick inspection and place monitors in most apartments, and the method detected almost 4X more infested apartments than management was aware of. Her work provides yet more proof that relying on residents and staff to report bed bugs is ineffective, and that building-wide inspections are a must for effective bed bug control in high rise apartments.

The power of genomic testing never ceases to impress me.  Ed Vargo, Texas A&M University, shared the work of his student, Andre Eyer, who took a critical look at the tawny crazy ant genome (DNA fingerprint).  He wanted to know whether previous research was correct that found tawny crazy ants live in super-colonies.  Super-colonies house many queens per nest, may consist of millions to billions of ants and can extend for many miles.  Super-colonies may look like many individual ant colonies with individual nests; however, the ants in these colonies are all closely related and may in fact move freely from one colony to the next.  Previously the only way to test for super-colonies was to put together ants from different nests and record levels of aggression.  Eyer did this, plus looked at the diversity of alleles (different forms of a gene) in U.S. crazy ants vs. crazy ants from the native home in South America. He found low aggression among different TCA colonies and only half of the genetic diversity in introduced vs. native ant populations. His results confirm that TCA ants do form super-colonies, and that all the crazy ants he tested likely came from a one-time introduction (to the US).  This information may not be super-practical in terms of controlling crazy ants, but it puts scientific management of tawny crazy ant on a firmer scientific footing.

Thomas Chouvec, University of Florida, conducted some interesting experiments with Cryptotermes gestroi, a relatively new invasive termite in south Florida. Conventional wisdom suggests that fipronil is “invisible” to termites in the soil, making it possible to eliminate termite colonies through contamination. The idea is that termites travelling through contaminated soil blithely carry insecticide back to the colony, damaging or eliminating it. Using a more realistic lab assay technique with long foraging tunnels (similar to real foraging tubes), Chouvec showed that C. gestroi appears able to detect problems with nest mates returning from fipronil-contaminated tunnels.  In lab experiments the termites were able to maintain their colonies even when part of the colony was visiting so-called fipronil “death zones.” This finding suggests that fipronil may not work as effectively against C. gestroi, a cousin of the Formosan termite. More work, I’m sure, is coming on that idea.

Other worthwhile take-aways from this year’s meetings:
  •  If you battle tawny crazy ant in your community, you might be interested in the new crazy ant videos shown by Kelly Palmer, Alabama Cooperative Extension.  Topics range from an introduction to the ants, their habitat, management and preventing infestations. Each is less than three minutes long and features an expert in ant management.
  •  Johnalyn Gordon reported on what could be the next tawny crazy ant. Plagiolepis alluaudi, the little yellow ant, is a new invasive ant in south Florida.  It lives in leaf litter, and though it doesn’t sting, its large numbers and invasive behavior could make it a major pest in some areas, similar to tawny crazy ant. 
  • Bob Davis, BASF, reported 30-60 days control of striped scorpions with the new microcap insecticide Fedona®.  Microcap products provide control even on tough surfaces like concrete and soil.
  • Venerable, retired entomologist Mike Rust is still cranking out helpful information about flea control.  Using a statistical method developed for testing anti-cancer drugs he looked for synergism (a 2+2=6 effect) between common insecticides and insect growth regulators. He found variable results with some combinations working well and others not (for example, pyriproxyfen synergized fipronil, while methoprene did not; methoprene did synergize imidacloprid, but not vice versa). He concluded that IGR mixtures must be tested; and results cannot be reliably predicted.
  • Dini Miller was one of the few speakers to talk about digital innovations in pest control.  She is field testing a new Delta Five remote insect monitor for insects.  As an insect enters a Delta Five trap a picture of the invader is sent to a phone app. With a technician’s time worth about $1.50 a minute, Miller thinks that remote alerts from traps like this could save a lot of labor cost, especially monitoring bed bugs in large hotels. She did not address efficiency of the units in detecting low level bed bug infestations.
  • Coby Schal looked at behavioral aversion among German cockroaches to baits, and found that pesticide-resistant cockroaches may be at a disadvantage in a pesticide-free environment. For example, he found that glucose-averse, resistant-females have lower mating success.  This could be why bait rotation has been effective so long in keeping glucose-averse cockroaches from taking over the world.
  • Freder Medina, BASF, reported that over 6 million homes have been treated with fipronil since its introduction as a termiticide in 2000. The newest formulation and application system, HP II, has been tested on 81 homes so far, with a 98% elimination rate after 3 months. The new system relies on high pressure injection and a unique waterless formulation to eliminate the need for tank mixing.
  • Finally, if you haven’t seen it, you need to “meet the caste” of the new Tiny Termite House. Professionally produced and expertly photographed, NPMA worked with the City of New Orleans to build and infest an incredible, 1:16 scale house with termites. The purpose is to “raise awareness of the destructive nature of termites.” The videos show the house being consumed by 500,000 hungry Formosan termites.  If your company maintains a newsletter or blog, the videos are definitely post-worthy.  Your customers need to see this.
I overheard one entomologist comment that for her, the NCUE was the most important conference she attends all year. I agree. The smaller size and narrow focus of the meetings, means that NCUE is usually a perfect fit for the geeks among us in the structural pest control industry. This year's meeting was no exception.

Thursday, June 21, 2018

Moving Beyond Mallis: Young Entomologists at NCUE


The biannual National Conference on Urban Entomology (NCUE) is always a treat.  It’s a relatively small conference with a personal feel. Many attendees know each other personally, and new students get to learn more about urban entomology outside their labs and classrooms. This year’s meeting in Raleigh, NC attracted about 200 students, university faculty and industry urban entomologists, including a score of researchers from the joint invasive pest ant conference.

When I attend NCUE I see folks whose lives and careers I’ve followed for many years, as well as new faces who are the future of our industry.  I hear controversy in discussion sessions as researchers politely prod speakers to think more deeply about their research results (entomologists are almost always polite); and sometimes I hear talks that will change the way I view structural pest control. While there were no real revelations at this meeting, many of the talks I heard this year fell into the category of “baby steps” toward better pest control and deeper understanding of the biology of structural pests.

Every NCUE meeting has a Distinguished Achievement Award recipient. This year’s honor went to Brian Forschler, a respected termite researcher from the University of Georgia. It was his job to open the meeting with a tribute to Arnold Mallis, who many of you know by his “ten-pound” Handbook of Pest Control. 

In the 1940s and 50s Arnold Mallis was a
rising star in the field of urban entomology.
Forschler noted that Mallis filled a desperate need at the time for science-based information on household insect pests. Though he had little to say about IPM (the concept hadn’t been formally proposed), in his books he summarized critical biological information upon which IPM programs could later be built. Mallis taught us that urban entomology is built upon a firm foundation of education and engagement with its stakeholders. Forschler urged each attendee, especially each student, to consider new ways to engage outsiders with urban entomology, while being the same consummate entomologist, naturalist and observer of insects as Arnold Mallis.

After Forschler’s session, the meeting began with papers from student award winners.  When I listen to students I always keep in mind that today’s students are tomorrow’s experts.  In just a few years these will be the folks making the rounds at CEU meetings for NPMA and other professional gatherings, so it pays to listen and make note of the new faces.

Emily Vernon, Bachelor of Science Student Award winner came from North Carolina State University where she studies Blattabacterium, a genus of symbiotic bacteria that live within special bacteria-hosting cells of cockroaches. These bacteria, she proposed, are essential to the German cockroach’s ability to survive in nitrogen-poor environments. In her research with 16S ribosomal RNA primers she detected high levels of variability in Blattabacterium in field populations of cockroaches, leading her to pose the question: “if we can manipulate Blattabacterium in the cockroach, might we be able to control cockroaches in the field?” I don’t know the answer, but I do know that when I was her age my most profound questions dealt with where to go for pizza on Friday night. Wow!

Master’s Student Award winner, Danielle Hoefele, Simon Fraser University, tackled a whole new structural pest, the European fire ant, Myrmica rubra. Think of it as a fire ant for the north.  The European fire ant is spreading into British Columbia and Washington State, as well as New England and eastern Canada.  It’s an aggressive ant with a sting that itches up to 10 days.  Danielle looked for different food sources that might work well in a fire ant bait. She found that baits combining carbohydrates and proteins were most attractive. Ultimately, she hopes to design a custom bait to provide a much-needed control option for this pest.

The herb thyme is a natural source for the monoterpene oil,
thymol, which has promise as a natural insecticide against
bed bugs. Relatively few plant oils have been investigated for
use in urban entomology. 
Sudip Gaire from Purdue University was the Ph.D. Student Award winner for his studies on the effects of plant essential oils against bed bugs. Sudip is pursuing more effective, safer, natural insecticides for bed bugs.  By looking at plant essential oils that have not previously been tested, he hopes to discover better options for controlling insecticide-resistant bed bugs.  He found carvacol, thymol, and citronellic acid to have to be the most toxic plant oils, none of which is currently in use against bed bugs. It may be years before these products are successfully brought to market, but Sudip is starting the process, and he reminded me that the field of essential oils for pest control is ripe for mining.

In another student paper, Sanjay Basnet from the University of Nebraska, is looking at ways to turn the bed bug’s own genetic material against itself. Interference RNA, or RNAi, are small RNA strings found naturally in the cell that help block expression of target genes. A few years back, someone got the bright idea that if we could find the right RNAi strings we might be able to use them as insecticides to turn off genes that are critical for an insect’s survival or reproduction. Sanjay thinks he may have found such an RNAi strand—one that can reduce egg production in bed bugs.  When injected into bed bugs this natural and biodegradable molecule reduced average daily egg production from 6/day to 0/day at 3 and 4 weeks after treatment. Much more work is needed to bring this kind of technology to your company; but its always encouraging to hear about any progress in this area.

One of today's rising stars of urban entomology is Zach DeVries, PhD student at North Carolina State under major professor Coby Schal.  DeVries is looking at a previously ignored component of bed bug aggregation pheromone called histamine.  You’ve probably heard of histamine. It’s an important chemical that our bodies produce to regulate our local immune response. On the positive side, histamine allows capillaries to become more permeable to our white blood cells so they can engage pathogens during an infection.  On the downside, it’s the chemical that causes inflammation and itching after an insect bite or exposure to an allergen. That’s why you may take an antihistamine drug for a runny nose or itchy eyes. Histamine also affects numerous organs, causes increases in heartrate, and difficulty breathing.

DeVries and colleagues inspected house dust from homes with and without bed bugs. They found up to 25X higher levels of histamine in bed bug-infested homes. They also found that histamine persisted for 3-6 months after an infestation had been eliminated. Whether these relatively low levels of histamine associated with bed bugs will have chronic effects on human health is unknown. But if significant, DeVries’ team’s discovery could be as important to pest control as the discovery of the link between German cockroaches and asthma in the 1990s.

DeVries also gave a second, more controversial, paper on progress towards developing a liquid bait for bed bugs. He suggests that liquid baits might offer an alternative insecticide-delivery method that could bypass at least one of the resistance strategies used by bed bugs (such as thickened, pesticide resistant cuticles).  So far, De Vries has identified good active ingredients (such as fipronil, neonicotinoids, and DMSO) for such a bait.  The feeding attractant for bed bugs is more of a challenge, however. Bed bugs eat blood of course, which is not likely to be stable in a bait formulation. And who wants blood-filled bait stations around their home?  He found that simple salt water, with or without the natural cellular compound adenosine triphosphate (ATP), made an attractive feeding stimulant for bed bugs.  The challenge, he argues, is to come up with a way to deliver this tasty insecticide to hungry bed bugs.  

But some listeners gently challenged DeVries to demonstrate how baiting might be more effective than a good trap, say.  The reason that most cockroach, termite and ant baits are so effective, is that they don’t just kill the individuals that come to the bait. They are effective because they kill the feeders and their companions. This happens when other cockroaches eat the feces or dead bodies of bait-fed cockroaches, or when ants and termites share their toxic meals with nestmates. At this point it’s hard to see how you might get secondary kill with bed bugs. Time will tell whether NCSU researchers will demonstrate the practicality of blood-mimicking bait stations; but it’s a thought provoking idea, and I’m glad someone is exploring it.

Whew. That was just some of what I learned from students at NCUE last month.  In my next installment, I’ll cover some of the highlights from veteran urban entomologists in Raleigh.