CONTROL OF GERMAN-COCKROACH (DICTYOPTERA, BLATTELLIDAE) WITH RESIDUALTOXICANTS IN BAIT TRAYS

Bait trays that contained a bait base surrounded by a surface treated with residual treatments of pyrethroids, an organophosphate, and a car bamate were evaluated for German cockroach, Blattella germanica (L.), control. LC(50)s of baited residual insecticide deposits were 1-3 mu g /cm(2) for lambda-cyhalothrin, 7-29 mu g/cm(2) for cypermethrin, chlor pyrifos and cyfluthrin, 55-150 mu g/cm(2) for permethrin, and 431-852 mu g/cm(2) for bendiocarb. Plastic surfaces provided greater mortality of all stages of German cockroaches at 24 h than aluminum foil and fi lter paper surfaces; for instance, cypermethrin killed 100% of males o n plastic compared with 90% on aluminum and 70% on paper. Also, wettab le powder formulations killed significantly higher percentages of Germ an cockroaches than did emulsifiable concentrates and technical active ingredient. LT(50)s of cockroaches confined to treated surfaces were 0.94-1.64 min for cypermethrin and lambda-cyhalothrin, 2.09-4.11 min f or cyfluthrin and permethrin, and 15.12-21.62 min for chlorpyrifos and bendiocarb. The use of an inedible bait base significantly enhanced k ill of bait trays treated with cypermethrin; 94% of male cockroaches d ied in 4 d with baited trays compared with 43% mortality with trays co ntaining no bait.