a device for detection of residual activity of beta-cyfluthrin (responsar 12.5% sc) as a new pyrethroid on different species against blatella germanica (orthoptera: blattellidae)

this study was designed to evaluate the efficacy of beta-cyfluthrin (responsar 12.5% sc), against a standard susceptible strain of german cockroach, blattella germanica, using three different dosages, at three different exposure times, on two types of surface, parlous (mosaic) and non parous (glassed ceramic of tiles). comparison of the resifts indicated that beta-cyfluthrin at 12.5 a.i.mg/m2, has negligent residual activity on both mosaic and glazed ceramic tiles from one to two weeks. however at 25 a.i.mg/m2 (highest dosage), had the longest residual activity on mosaic, it was active for six, seven and nine weeks, while on glazed ceramic tiles the residual activity increased slightly to seven and nine and nine weeks, when the nymphac were exposed for 10, 15 and 20 min, respectively. these results of the bio-assay test indicate that 12.5 a.i.mg/m2 is too low for any residual spraying. application of beta-cyfluthrin at a target dosage rate of 25 and 37.5 a.i.mg/m2 showed longer residual deposit effect than the earlier dosage. hence these dosages could be recommended for light and heavy infested area, respectively. this study is also recommends a simple device for measuring the residual activity of insecticides against german cockroach either in laboratory or in the field conditions.