Catching the new drift on pyrethroids

For years agricultural pesticide applicators have been required to measure and record wind and weather at the time of spray applications. Wind matters in agricultural applications because of the potential for pesticide drift--the movement of pesticides from their intended target to undesirable sites such as other farm fields, homes, schools and natural areas. Weather matters because excessive rainfall can result in poor adhesion of sprays to plant or soil surfaces and pesticide-contaminated runoff--another form of drift.

In structural pest control, drift has always been an issue also, but on a much smaller scale.  For structural pest control indoor applicators, drift can occur in the form of splashback during both spot and crack and crevice liquid insecticide applications indoors. It can also occur with dust applications (I still remember my dismay, as a young and inexperienced applicator, when a compressor fan kicked on, blowing the pyrethrins dust I had just applied to a cockroach-infested motor back in my face). Outdoor applications can "drift" under windy conditions, or when rain washes residues from the application site to streams or lakes.  In fact, pesticide runoff is the reason that EPA has moved recently to change labeling requirements on new pyrethroid insecticide labels.

The new pyrethroid label standards by the US EPA are now out, and should be on every pest control service manager's required reading list. Unfortunately, they are not that easy to find, nor understand. I recently had the opportunity to sit in on the webinar update on these new standards by Jim Fredericks of the National Pest Management Association. NPMA has been working hard to keep up with these new standards and Jim did a nice job summarizing the new use directions you will be seeing shortly on all pyrethroid pesticide labels.

Digital handheld wind meters are relatively inexpensive,
accurate and can have powerful options such as wind
direction, temperature and relative humidity.

Two weather-related issues appear in these new requirements. First, for pre-construction termiticide applications only [see update in the May 1 comment below], the new labels will say,“Do not make on-grade applications when sustained wind speeds are above 10 mph (at application site) at nozzle end height.”  This means that anyone doing pre-construction termiticide treatments will have to have some method of measuring wind speed [as far as I can tell wind speed measurement is not required for general pest spray applications around residences and businesses].  There are at least three ways I know to estimate wind speed accurately:

• Purchase and use a digital wind meter, like the one in the accompanying image.  Today's units range in price from $20 to $200, depending on features. They can include barometric pressure, relative humidity, temperature, altitude, etc.
• Get a old-fashioned Dwyer handheld windmeter for about $25. This tough and dependable unit (doesn't need batteries) works on air pressure to elevate a small plastic ball, providing a simple wind speed measurement.
• Go to an online website that provides windspeed data for your location, such as  http://www.intellicast.com/National/Wind/WINDcast.aspx. The problem is that the wind speed at your local airport may not be the same as at the account where your applications are made.

Second, the new labels will prohibit any pyrethroid spray, granular or dust applications made when it's raining. In areas where rain is frequent, or constant at certain times of year, this may be inconvenient (and who's to say when it's really raining?), but the intent is clear.  When it's raining, insecticides will not adhere well to surfaces and are prone to running off the target site into storm drains or streams.

Finally, anyone doing outdoor applications (especially termite pre-treatments) should consider adding spaces on your business' service forms for weather data, like wind speed and precipitation. If you're an honest applicator who goes by the book, this sort of information can only help you if called upon to defend an application.  An on-site reading taken from a handheld wind unit always trumps NOAA area weather data, and could save your rear in a legal case.  

The bed bug challenge

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.
  
• 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.