ABSTRACT The control of Alphitobius diaperinus is based mainly on chemical insecticides, and the indiscriminate and incorrect use of these products has led to failures in insect control. Thus, it is important to monitor the efficiency of the products available on the market and to develop alternative insect control strategies. The present study evaluated the effect of a new product (cypermethrin-6%) under laboratory and field conditions and assessed its in-vitro compatibility with the fungus Beauveria bassiana (Unioeste 4 isolate). Its efficiency in dry powder and wettable powder formulations was also assessed in the laboratory through comparison with a similar insecticide (cypermethrin-5%) at five different concentrations. The field assays were conducted in two commercial broiler breeder houses (Treated and Control), applying the new product on the litter at the manufacturer's recommended concentration (RC). Germination, vegetative growth, conidial production, number of colony forming units (CFUs) and insecticidal activity of the fungus were used to evaluate the compatibility of the insecticide. The effects of the cypermethrin-6% product and cypermethrin-5% were equivalent in the laboratory, and the new product exhibited better performance at lower concentrations (1/4RC, ⅛RC). The strategy applied in the field reduced the insect population in up to 96% after 75 days. Additionally, all concentrations of cypermethrin-6% were compatible with the fungus under the evaluated in-vitro conditions. Therefore, the new product is considered selective for B. bassiana. Further studies are necessary to assess its compatibility under field conditions, consolidating this strategy as a viable alternative for managing this pest.

ABSTRACT This study aimed at evaluating the effect of the use of disinfectants and insecticides recommended for the control of pathogens and insects in poultry houses on the biological parameters of the entomopathogenic fungus Beauveria bassiana strain Unioeste 4. Disinfectants and insecticides were used at recommended concentration (RC), half the recommended concentration (0.5 RC), and twice there commended concentration (2RC). All treatments were sprayed on the fungus previously inoculated on PDA culture media. Germination, colony forming unit (CFU), vegetative growth and conidial yield were evaluated. Germination was the most affected parameter by insecticides, with reduction of up to 25% using Couro Limpo and Cypermil products. Cypermil also reduced the vegetative growth in all tested concentrations. Conidial production was reduced when products were used at the highest concentration. On the other hand, the confirmed mortality of the lesser mealworm by the fungus was not affected by none of the tested products. All disinfectants at the highest concentration reduced germination and conidia production, but did not affect fungus vegetative growth. The confirmed mortality by the fungus was most influenced by the product TH4. All tested products tested were considered compatible with the fungus.