Research News For Pest Control Professionals

GERMAN COCKROACH RESEARCH

Toxicity of Fipronil To Susceptible and Resistant Strains of German Cockroaches (Dictyoptera: Blattellidae) and House Flies (Diptera: Muscidae). 90(5): 1152-1156. Jeffrey G. Scott and Zhimou Wen, Department of Entomology, Cornell University, Ithaca NY 14853-0901.

Fipronil (the new active ingredient in Maxforce FC) was highly toxic to susceptible and resistant strains of German cockroaches and house flies. Extremely low levels of cross-resistance were detected when this product was used against highly resistant strains of German cockroaches and house flies, suggesting that cross-resistance will not be a limiting factor in the use of fipronil against these species.

Comparative Contact Activity and Residual Life of Juvenile Hormone Analogs Used for German Cockroach Control. 90(5): 1247-1253. Walid Kaakeh, Michael E. Scharf and Gary W. Bennett, Department of Entomology, Purdue University, West Lafayette IN 47907-1158.

This study investigated the persistence and contact activity of three juvenile hormone analogs (JHAs), i.e. fenoxycarb, hydroprene and pyriproxyfen, for the control of German cockroaches when applied at clean-out rates to three surfaces (tempered masonite, stainless steel and unpainted plywood) over a four-month period and under severe environmental conditions. Aging the treated panels under greenhouse conditions, fenoxycarb remained very effective for 60 days but declined significantly after 90 days. The effectiveness of hydroprene and pyriproxyfen declined significantly at 30 days. Under laboratory conditions, fenoxycarb remained effective on all surfaces for 120 days. Hydroprene remained effective on all surfaces except stainless steel for 90 days, and pyriproxyfen remained effective on stainless steel for 120 days but was only effective on the other surfaces for 30 days. To maximize the effects of JHAs, the environment and application surfaces must be considered and the products must be reapplied regularly. Cockroach population reduction is enhanced by the use of JHAs and baits and/or residual pesticide applications.

Use of German Cockroach Fecal Extracts to Enhance Toxic Bait Performance in the Presence of Alternative Food Sources. 90(2): 483-487. D. M. Miller, P. G. Koehler and R. S. Patterson, Department of Entomology and Nematology, University of Florida, Gainesville FL 32611.

In the presence of five alternative food sources, the use of German cockroach fecal extracts in combination with hydrameth-ylnon and chlorpyrifos bait significantly increased the performance of the bait (mortality) from 30% to 60% in five and seven days respectively. Ultimately the use of fecal extracts may increase the efficacy of bait stations, decrease bait repellency and overcome the effects of competing food sources. This also underscores the value of placing baits in areas where fecal deposits are observed.

Evaluation of Trapping and Vacuuming Compared with Low-Impact Insecticide Tactics for Managing German Cockroaches in Apartments. 90(4): 976-982. Walid Kaakeh and Gary W. Bennett, Department of Entomology, Purdue University, West Lafayette IN 47907-1158.

The use of sticky traps and vacuums to reduce German cockroaches in multi-family housing units were compared to residual insecticide treatments and baiting. In 1995, various control procedures were evaluated four weeks post-treatment and provided the following percentage reductions in German cockroach populations: Siege gel bait (82.4), Victor pheromone sticky traps (79.3), flushing and vacuuming (80.2), vacuuming (72.5), and Empire 20 spray (72.0). In 1996, two additional pest management procedures were evaluated eight weeks post-treatment and provided the following percentage reductions in populations: Knockdown pheromone boric acid bait (83.7), Victor Roach Pheromone sticky traps (80.1) and Suspend spray (68.5). The use of a synergized pyrethrin flushing agent facilitated the removal of cockroaches that were in inaccessible areas of deep harborages and increased the removal of gravid females. The study results indicated that in heavily infested multi-family housing units, vacuuming/flushing and pheromone cockroach sticky traps are equally effective to baits and residual sprays in reducing German cockroach populations.

BORIC ACID VS. PHARAOH ANTS

Liquid Boric Acid Bait for the Control of Structural Infestations of Pharaoh Ants. 90(2): 523-526. John H. Klotz, Karen M. Vail and David F. Williams, Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, 1600-1700 SW 23rd Drive, Gainesville FL 32608.

A 1% boric acid-sucrose water solution was used to effectively control foraging pharaoh ants in several structures. Ants were baited over a period of three weeks with the bait stations being replaced weekly. Significant reductions in the number of foraging ants were obtained during the first week, and this level of control was maintained for the next seven to eight weeks. The 1% concentration is much lower than concentrations of boric acid in commercially available baits. At this low concentration the boric acid-sucrose bait is slow-acting and less likely to be repellent. In addition, this bait offers the additional advantages of an attractant and a moisture source.

FROZEN TERMITES

Evaluation of Freezing to Control Wood-Destroying Insects. 90(5): 1215-1221. Michael K. Rust, Eileen O. Paine and Donald A. Reierson, Department of Entomology, University of California- Riverside, Riverside CA 92521-0314.

This study determined the critical temperature necessary to kill various stages of wood-destroying insects using liquid nitrogen in a mock-up wall void. The minimum critical temperatures for workers of the western drywood termite and the Formosan subterranean termite were -21.3C° and -13.9°C, respectively. Minimum critical temperatures for eggs and small, medium and large larvae of the southern lyctus beetle were -35.6°C, -26.2°C, -30.0°C and -24.3°C, respectively. The rate and height at which the liquid nitrogen was introduced into the wall void and insulation affected the rate of cooling. Because the extent of cooling is very limited, many, if not all wall voids, may require treatment. Applications should be closely monitored using thermocouples.

In the study, plumbing and electrical fixtures in the wall were unaffected by low temperatures, however, vinyl tiles at the base of the wall cracked. Also, the use of liquid nitrogen leads to significant oxygen depletion and can be a safety factor for applications.

Dr. Richard Kramer is president of Innovative Pest Management, a consulting firm based in Olney, Md. He is a former technical director of the National Pest Control Association. To contact Dr. Kramer, call 301/570-7138.