Deltamethrin residual mission against Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) on concrete for six weeks

Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is an important pest of stored-products and poultry houses. Despite the fact that there is knowledge about chemical management of this species, there are no data about the residual efficacy of deltamethrin. Therefore, this study compares the immediate and delayed efficacy of half label and label dose of deltamethrin treated on concrete surfaces, with or without food, over a six-week period against A. diaperinus adults and larvae. In first week, both doses of deltamethrin exhibited the highest immediate and delayed mortality at all food/no food scenarios, for both developmental stages, whereas its efficacy gradually decreased over the experimental period. Concerning adult mortality, it ranged between 6.7% and 31.1% the first week, while 1.1-13.3% the sixth week, after 7 days of exposure. Both doses exhibited elevated efficacy against A. diaperinus larvae. Label dose without food caused 100.0% mortality the 3rd day whereas label dose with food the 7th day of the first week. Total mortality (100.0%) was recorded at the end of the second week by both food/no food scenarios of label dose. The third week only label dose without food killed all larval individuals, the 7th day. During the sixth week, mortality ranged between 71.1% and 92.2%, at the termination of the experiments. Concerning delayed adult mortality, it ranged from 63.6% the first week to 7.9% the sixth week. As far as delayed larval mortality is concerned, all individuals died even the fifth week at label dose without food, the fourth week at label dose with food, the second and the first week for half label dose without food and with food respectively. Deltamethrin has elevated efficacy against A. diaperinus larvae despite the dose and food presence/absence.