Laboratory evaluation of insecticide gel baits for control of Supella longipalpa (Dictyoptera: Blattellidae)

Abstract:
Five insecticide bait formulations have been evaluated for their attractiveness to adults of Brown-banded Cockroach, Supella longipalpa (F.) in laboratory trials. The gel formulations contained one of the following active ingredients (a.i.): hydramethylnon, imidacloprid, fipronil. Tests were carried out in plastic boxes (73 cm x 55 cm x 16 cm) in a climatic room (24° C; 60% RH), with 10 adults (5 males and 5 females). Every gel has been tested four times in presence of food source, water and cardboard shelter. According to these tests, the attractiveness of gels decreased in the course of time; the majority of the adults have been killed in the first week than in the second and third ones. There were significant differences among the baits in their attractiveness to the Brown-banded Cockroach. The most effective gels were those with hydramethylnon and with fipronil 0.05%. After one week, more than 50% of the adults have been killed with tested hydramethylnon formulations and with fipronil 0.05% gel. In the following two weeks, the number of killed cockroaches has increased and in the test with hydramethylnon 2% formulation, the mortality rate was 100%. The formulation with fipronil 0.03% killed in three weeks about 50% of the adults. The worst gel was the one containing imidacloprid, which killed after three weeks less than 50% of the cockroaches.