[Technically Speaking] Noteworthy pest management research

There is a lot of research that is done that benefits our industry — unfortunately, only a select few in our industry have the opportunity to read it. In most cases we hear snippets of research information at state and national pest management meetings and rarely are presented all the information or afforded the opportunity to read it ourselves.

It was interesting to note in my most recent visit to the Entomological Society of America Web site (www.entsoc.org/Pubs/Overview/index.htm#Periodicals) that you do not have to log in (just skip it) to view the articles in all ESA journals and read the abstract. Furthermore, some of the abstracts offer a free PDF download of the entire article.

The following are a couple of articles published in the Journal of Economic Entomology (2006):

Rust, M. K. and R. K. Saran. Toxicity, repellency, and transfer of chlorfenapyr against western subterranean termites (Isoptera: Rhinotermitidae). 99(3):864-872. University of California, Riverside

Since the introduction of Termidor several years ago, there has been a lot of research and discussion on the virtues and efficacy of non-repellent termiticides. I suspect that some pest management companies have begun to test the limits of these products by seeing how little they can apply and how many treatment corners they can cut and still be successful. This research perhaps portends the consequences of pushing these products too far.

Label rate applications of chlorfenapyr at 0.25 percent provides a soil residual of approximately 200 ppm. The study found that termites exposed to more than 75 ppm for one hour resulted in 70 percent mortality at seven days. At a lower concentration of 50 ppm after one hour of exposure, 17 percent of the termites showed reduced responses to trail pheromone and after four hours about 60 percent of termites did not respond to the pheromone. Transfer of the product ingredient to recipients ranged from 13.3 to 38.4 percent. A one-hour exposure to 100 ppm provided 100 percent mortality of direct recipients and 96 percent mortality of exposed recipients; however, there was not enough toxicant on these recipients to produce mortality in additionally exposed termites.

The authors conclude, "There is a dynamic relationship between the inherent toxicity of an insecticide, the exposure dose, the exposure time and the onset of toxicity that dictates the likelihood of horizontal transfer." What can be gleaned from this with regard to non-repellent termiticides is if the concentration of the product is too high termites will die before transfer can occur; if the concentration is too low the termites do not pick up enough product for secondary exposure to occur; as higher initial concentrations decrease the horizontal transfer kicks in. Thus, we still do not have a silver bullet for termites and behooves companies using the non-repellents to follow the recommended application rates and not to rely solely on a barrier treatment to resolve the problem.

Wang, C. and G. W. Bennett. Comparative study of integrated pest management and baiting for German cockroach management in public housing. 99(3): 879-885. Purdue University

This study affirms what most of us already know — bet on the cockroaches. The 29-week study compared baiting alone with IPM (baiting, trapping, vacuuming and tenant education). I take issue with calling the alternative treatment IPM because the approach taken by the investigators leaves elements of an IPM program out that perhaps would have improved the overall effectiveness of their interventions. However, the study does indicate that education is an important component of an IPM program.

Six traps were placed in each apartment to monitor cockroach activity and measure the success of the two treatments. At 16 weeks, trap catch reductions in the IPM group (100 percent) were significantly greater than the bait only group (94.6 percent); however, at 29 weeks the trap catches were not significantly different 98.3 percent and 85.8 percent. You may question why there was 100 percent control at 16 weeks and 98.3 percent at 29 weeks — the simple answer lies in the counting method, i.e., sticky monitors. The authors reported visually seeing cockroaches that are not accounted for by monitors. A small percentage of the apartments in both groups had cockroaches at the end of the study.

The authors (and I) believe that in most of our experience, customer education in these situations is of paramount importance. This was accomplished in the study by recurrent attempts to educate the tenants. For the most part, they found that sanitation in the IPM apartments was significantly improved at the end of 29 weeks. Typically, sustainability of sanitation over extended periods of time is extremely difficult in apartment settings.

The cost of providing the "IPM" 29-week program as described in this study is also worthy of note:

• IPM — mean $65/unit; range $17-$234. This did not include education, repair and sanitation expenses.

• Bait — mean $35/unit; range $11-$81

Some of the take-away messages from this study are:

• IPM as defined in this study does not eradicate cockroaches.

• IPM that includes other elements is very expensive and time consuming.

• Many property managers prefer a complaint-based approach to pest management. This method saves money but allows infested units to go untreated.

• Trapping can be used as an effective means of directing bait applications.

• Besides removing cockroaches, vacuuming has added value in allergen reduction.

• Baits can perform well despite poor sanitary conditions.

• Clutter and obstacles were the major impediments to cockroach eradication.

• Money, contract specifications and tenant motivation are the major factors in cockroach management in public housing and apartments.

Research conducted by private and state universities is or great benefit to our industry. We need to support their efforts every way possible.

The author is president of Innovative Pest Management, Brookeville, Md., and can be reached via e-mail at rkramer@giemedia.com or at 301/570-3900.