مقايسه اثر چند حشره كش در روي سوسري آلماني BLATTELLA GERMANICA CL. BLATTARIA:BLATTELLIDAE

Comparision of the effects of some insecticides on German cockroach, Blattella germanica (L.) (Blattaria: Blattellidae)

Due to increase of resistance in German cockroach (Blattella germanica) to insecticides. the effects of some organophosphorus and pyrethroid insecticides were evaluated in dormitories of Ferdowsi University of Mashhad. These places were frequently under intense pressure of different insecticides. The tests was carried out on two growth stages of German cockroach (first instar nymphal of 3-5 days aged and adult females of 1-5 days after laving the ootheca). Six different insecticides (Permethrin, cypermethrin, Lambda cyhalothrin, Diazinon; Prymphos methyl and Chlorpyriphos) each in three levels of concentrations (0.003, 0.006 and 0.009) were used. The results were compared in a factorial experiment based on randomized complete block design with 4 replications. The comparision mean of mortality tests indicated that lambda cyhalothrin caused the highest motality on the nymphs and adult females in the least of test time and in the lowest concentration. The mortality effects of chlorpyriphos, pr_vmphos methyl and lliazinon were relatively satisfactory, but effects of permethrin and cypermethrin were not desirable. ]n most cases the nymphs showed more susceptibility to insecticides than the adult females. Knock-down tests by pyrethroid insecticides indicated that lambda cyhalothrin had the highest effect and cypermethrin the lowest effect on nymphs and adult females of German cockroach.