Friday, March 26, 2010

PCT article and request for feedback on use of bed bug traps

Check out the PCT magazine version of the bedbug research I posted about last month from Rutgers University. One nice thing about this version of the article is that it shows pictures of the bed bug interceptor traps in use.  To my knowledge this is the first reported successful use of unbaited Climbup® interceptor traps being used to monitor bed bugs. 

Click image to view article
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Understanding Bed Bug Infestation And Dispersal Patterns

I'm curious how many of you have used these types of traps and whether and how well they have worked for you.  If you have experience with monitoring/inspecting for bed bugs, would you consider answering a few questions about your experience? If so, click here to go to a brief Survey Money questionnaire. I will publish results shortly.

Monday, March 22, 2010

Monarch Update

Once again, Insects in the City is ahead of the curve.  Our early news last month about monarch butterflies is being confirmed in the newspapers this week.  Gardeners in urban areas are being encouraged to plant milkweed to provide some extra food sources to help migrating butterflies this summer and fall.

Monarch butterflies making trek north from Mexico in lowest numbers in decades
Fort Worth Star Telegram By BILL HANNA


Monarch butterflies, hit hard by strong storms at their winter home in Mexico, have dwindled to their lowest population levels in decades as they begin to return to Texas on their springtime flight back to the
United States and Canada.

The monarch loss is estimated at 50 to 60 percent and means that the breeding population flying northward is expected to be the smallest since the Mexican overwintering colonies were discovered in 1975, said
Chip Taylor, a professor of entomology and director of Monarch Watch at the University of Kansas.

Thursday, March 18, 2010

National bed bug survey seeks your input

Passing on the following worthwhile information from Liza J. Fleeson with the Virginia Department of Agriculture:

"The National Pest Management Association (NPMA), in conjunction with the University of Kentucky, is interested in developing a better understanding about the re-emergence of bed bugs across the United States. To that effect, NPMA has asked that we reach out to the pest control industry and encourage you and your fellow pest management professionals to complete a voluntary on-line survey on this issue. The link to the US Bed Bug Survey is posted on our website at www.vdacs.virginia.gov/pesticides. The results will be published in a future issue of the PestWorld newsletter. The survey will run through March 22, 2010 but please consider completing it at your earliest convenience.

"Thank you for your participation. Should you have any questions, please do not hesitate to contact Jeffrey Rogers, Environmental Program Planner, OPS, at jeffrey.rogers@vdacs.virginia.gov or 804-371-6561."

This kind of information helps the entire pest control industry, so even if you're not an NPMA member or don't have bed bug woes now, please take a few minutes to respond. In a few years you may be dealing with bed bugs big time and your current experiences will make a nice contrast with today's answers.  Note: the survey is for PMPs only.

Texas Invasives

Urban pest management embraces all efforts to eradicate or manage a variety of organisms that are unwanted in the urban landscape.  The list of both indoor and outdoor pests includes insects, vertebrates, pathogens and plants.  Not that these organisms (like that cute raccoon in the creek by your home) are always pests, but when they are out of their place and into ours, they become pests.  A raccoon in your chimney is definitely a pest.

On the other hand there are certain organisms that are, by definition, always out of place.  We call them "invasives", and they are alien organisms that have made themselves noxious and unwelcome in our state or country. Last December I posted about a group called the Texas Invasive Plant and Pest Council (TIPPC), a non-profit organization to manage non-native invasive plants and pests in Texas.Yesterday TIPPC announced the public unveiling of their newly redesigned website.  I encourage you to check it out.  To get a real flavor of the spirit and impetus behind this group, especially check out the video.  It's a little on the long side at nearly nine minutes, but it will help you visualize the problem.  The video was made in Austin, Texas but the issue is real across the state and our nation.  At stake is native wildlife and plant diversity; and if that doesn't poke you where you feel it, consider this: your favorite fishing hole may be next!  Yes, invasive plants are a real threat to sports fishing and lake recreation, especially in east Texas and lakes throughout the southeastern U.S. 

If you're community minded, and interested in your local environment, there may be ways for you to get involved.  Visit the citizen science tab to learn ways to actively fight invasives in your town, whether it be in Texas or around the country.  Your skills as a PMP may be just what a local action committee needs.

Wednesday, March 17, 2010

Anthrenus verbasci: the "adaptable" carpet beetle

varied carpet beetle adult on Cheese-itsOne of the relatively common household pests that sometimes puzzles PMPs is the varied carpet beetle, Anthrenus verbasci.  The 3 mm-long adult is easy enough to recognize under magnification with its colorful zig-zag banding of white, black and orange scales.  The larvae are less commonly seen, but equally distinctive.  Cigar-shaped and hairy, they are often described by PMPs as banded, but close inspection reveals the banding to be the result of the darker colored dorsal plates contrasting with the lighter base color of the insect's body.

Varied carpet beetles might be better named the "adaptable carpet beetle" due to their catholic tastes in food. They differ in their eating habits from other beetles in the family Dermestidae, which normally require animal-derived proteins in their diet to survive and reproduce.  Examples of such other dermestid beetles include the black carpet beetle, the hide beetles, and the warehouse beetles.  The preferred foods of most dermestids include natural furs, feathers, wool, silk, dried milk and meats, taxidermy mounts and hides, dog food (with meat ingredients), dead insects, etc.  The varied carpet beetle readily feeds on these items, but can also subsist on a plant-based diet, such as drugs, spices, flour, nuts, wheat, corn, cereals and seeds.  Or, as I learned last night, the cheese crackers under my daughter's bed.

varied carpet beetle larvaMy youngest daughter is a Junior in college, and to judge from the archeological strata under her bed, the box of crackers probably dated from high school.  The discovery was prompted when my wife asked me what the two little larvae were under some books on our daughter's bed.  They turned out to be carpet beetle larvae, and the fact that there was more than one prompted me to go on a search and destroy mission.  Sure enough, the cracker box was soon located and the source confirmed. 

One thing I like about insects is that they never lie. If an insect is found indoors, there is always a reason.  An occasional carpet beetle may be found indoors after munching on dead insects in a light or windowsill, or from a bird nest or bee hive; but more than one is usually an indication of a problem.

The varied carpet beetle is not a good insect to allow to flourish in a home.  Along with its dermestid cousins, this beetle is one of the most likely culprits responsible for those mysterious holes in your favorite sweater.  As with all stored product insect pests, the best solution is not usually pesticides, but rather a thorough inspection to look for, and remove, likely food sources.  Last night's invasion was a relatively simple problem to solve.  Unfortunately, they are not all that easy.

Most dermestid-infested items are old, forgotten or spilled food in out-of-the-way places, old rodent baits in attics, or furs, feathers or woolens that do not get worn or used frequently.  Knowing something about carpet beetle biology and identification can help you solve those tough pest control problems for your residential customers.  Recognizing that you have a varied carpet beetle means you will have to widen your or your customer's search efforts to include plant-based foods.

My daughter's bed has now officially been purged of cracker boxes, dirty socks and high school notes.  Next time she's home from college, you can be sure we will tackle the CLOSET.  Who knows what new life forms we'll discover?

Monday, March 8, 2010

North Carolina study shows health benefits of IPM in schools

Just a short note about this story by Rosemary Hallberg at the Southern IPM Center.  I don't always have time to blog about all these great stories, so it's nice when someone else does the job for me.  Check out her article at http://ipmsouth.com/2010/03/05/study-shows-ipm-reduces-cockroach-allergens-in-schools/

Predicting termite swarms

termite swarmers emerging from an urban lawnOne thing PMPs will tell you they would love to have is the ability to predict the timing and severity of termite swarms in a given year.  Think about it.  If you knew exactly when termites would swarm, and how big a termite year it would be, your company could know when and how many employees to hire.  Pesticide distributors would know how much termiticide to order, and manufacturers would know what demand was going to be in a given year.  Lots of people would be lots happier.

Actually there is a research tool in IPM circles that attempts to do part of this.  Called a degree-day model, the technique is used to predict insect emergence.  It is based on the fact that insects are cold-blooded, and that development times of insects are linked closely with environmental (ambient) temperatures.  To use the method the relevant environmental  temperature is monitored and degrees for each day are added over time.  The adding is usually started in the dead of winter (January 1 or December 21, the first day of winter, are typical start dates), and a base temperature is selected over which degrees can be counted.  This base temperature varies for each insect, but it is generally the temperature above which development of the insect can proceed. An example of an insect pest whose development can be predicted with some accuracy is the pecan nut casebearer.

Unfortunately, termite swarming behavior is more difficult to predict with degree-day models.  For one thing termites remain active year-round.  Living underground and perhaps partially in heated structures, the ambient temperature of a termite colony would be difficult to monitor.  Most degree-day models are used to predict emergence from overwintering life stages, but PMPs need to know about swarming behavior, a behavior that is likely triggered by environmental conditions other than temperature alone.

A recent question I received about degree day models and urban IPM prompted me to look up a 2002 paper published by Barry Furman, a graduate of the urban entomology program at Texas A&M.  Despite the challenges of using degree days to predict termite swarm occurrence, Furman theorized that degree days might be useful to set the general time for swarmer (alate) termite maturity, and then base termite prediction on environmental triggers, specifically rainfall events, that occur after termites are ready to emerge.  Biologically this is a reasonable guess, because many people have noted that termite swarmers often cluster at the ends of swarmer tubes for several days before emerging, apparently waiting for the right conditions.  To estimate the dates of swarming over recent years, he worked with Orkin Pest Control branches in nine Texas cities to collect information about calls received concerning termites.

The data on swarming dates is fascinating by itself.  For the years 1994-1999, average initial swarm dates going from south to north in Texas were 24 February in Corpus Christi, 28 February in Houston, 28 March in Dallas, and 6 May in Amarillo.  The data do suggest the importance of heat unit accumulation for termite swarming.  Amarillo, the coolest location, experienced termite swarms more than 70 days later, on average, than Corpus Christi, the warmest location.  There was also a correlation between first dates of swarming and rainfall events.  Over 90% of initial swarming dates occurred within three days of a rainfall event.


Most of the swarm events over all the cities Furman studied occurred after heat unit accumulations between 640 and 680 day-degrees (°C), with no swarming noted before a heat unit threshold of 602 degree days. The authors concluded that tracking heat units through the year appeared to have merit in predicting the annual termite swarm.

So, how can this information be used?  This year appears to be cooler than normal, so the calculation might be an interesting exercise for Texas locations. I imported maximum and minimum temperature data from the weather station at the Dallas Center for December 21 to date, converted temperatures to Centigrade, and calculated degree days based on the formula for each day: DD=((max temp+min temp/2)-4), where 4°C is the base temperature Furman estimated, under which no maturation will occur.  If the average temperature for the day is less than 4°C, the accumulated DD for that day is zero (not a negative number, as the formula produces).  According to this calculation (the simplest of DD calculations) Dallas has accumulated only 272 degree days as of March 7.  If Furman and Gold's analysis is correct, we will need approximately 330 more accumulated degree days before swarming can occur in 2010.  With an average daily temperature in Dallas in March of 59°F (15°C), we would expect to accumulate approximately 11°C per day.  A tenuous calculation at best, but if the model is correct, we would not expect swarming any earlier than April 8 this year.  The prediction, of course, depends on temperatures for the rest of this month, but does suggest that swarms in Dallas might come a little later than normal this year.

The exercise demonstrates that so much research that is valuable to the pest control industry can sit on dusty shelves unless someone digs it up and makes it available for use.  This is Extension's job.  In the case of Furman's research on termite swarming predictions, we in Extension may have dropped the ball to some extent, not publicizing it as much as it deserves.  But also helps when researchers work closely with Extension scientists to ensure that research results are extended to the industry and refined so as to become practical.  In the case of termite prediction models, Furman and Gold's work undoubtedly needs more testing before it can confidently predict termite swarming dates.  As for predicting whether this will be a big swarming year, if I knew the answer to that I could make a lot of people happy.

Wednesday, March 3, 2010

Guidelines for killing bed bugs in laundry

The nice thing about an emergency pest problem, like the current bed bug epidemic, is that such problems attract a lot of attention from the research community.  A few weeks ago I reported new research from the Wang laboratory at Rutgers University on some interesting facts about bed bug infestations in high rise apartments. In the same journal two British scientists from the University of Sheffield, R. A. Naylor and C. J. Boase, report on another aspect of bed bug management...how to kill bed bugs in bedding and clothing using laundering procedures.

Knowing how to dis-infest clothing is important to pest control, because, as the authors so carefully explain, bedbugs "may seek harborage among clothing stored close to the bed, or may be entangled with bed linen while it is being changed. "  And, "once associated with clothing or linen, there is a risk that bed bugs may then escape insecticide treatments, and may be transported to new locations."

Although there have been many recommendations on the Internet and in print concerning how to dis-infest laundry, Naylor and Boase point out that such recommendations are often vague or conflicting and have been based on little formal research.  So they set out to look at the temperatures and conditions necessary to ensure 100% mortality of adult, nymph and egg stages of bed bugs.

To do this they took laboratory reared bed bugs and sealed them in cotton bags.  These bags were then placed among sheets or in the pockets of clothing to assess mortality of standard cleaning methods.   The results were enlightening and should help in recommendations for how your customers can ensure maximum effectiveness of methods to disinfest household articles.

A summary of the results of this study include the following:
  • Freezing can kill bed bugs.  Reducing temperatures to -17 degrees C (0 degrees F) for 2 hours will kill all bed bug life stages (about the temperature of a chest freezer, not a refrigerator freezer).  A 5.5 lb batch of clothes, however, does not drop to 0 degrees F immediately.  The researchers found that it took about 8 hours for the temperature in the center of that wad of clothes to killing temperature.  Upshot?  Put clothes in freezer for at least 10-12 hours.
  • Bed bugs are also susceptible to high temperatures of 40-50 degrees C (104-122 degrees F).  In order to reach these temperatures, clothing to be dis-infested can be placed in a large tumble drier at the HOT setting for at least 30 minutes (for a 7.7 lb load).  A 10 minute HOT tumble dry only killed about 75% of nymphal bed bugs, 85% of adults.  Interestingly, the COOL cycle killed almost no bed bugs.
  • Soaking clothes in cold water for 24 hours (without detergent) killed all adults and nymphs, but killed no eggs. Unfortunately, the researchers did not test whether soaking clothes in cold soapy water for 24 hours would kill eggs.  This alternative treatment might be useful, especially for cleaning clothes that are labeled for cool wash and dry only.
  • Dry cleaning killed all life stages of bed bugs, and would be an appropriate treatment for delicate and temperature sensitive fabrics.
  • When washing clothes, wash water at 60 degrees C (140 degrees F) on 30 minute wash cycles killed 100% of all life stages.  Washing at 40 degrees C (100 degrees F) killed all adults and nymphs, but only 25% of eggs.  So clearly, washing clothes for bed bug dis-infestation should be done at the hottest temperatures (about 140 degrees F).
Experience with many pests verifies the wisdom of using multiple control tactics to control pests--a basic tenet of IPM.  Certainly bed bugs are no exception.  Reducing clutter, systematic inspection and treatment of the bedroom and other infested rooms, trapping and ongoing monitoring, and effective treatment of all exposed household articles, including clothing, are all essential components of good bed bug control.  This research should help all of us with fabric dis-infestation.