Patogenicidade in vitro de uma formulação comercial de Metarhizium anisopliae sobre Alphitobius diaperinus

Abstract

Alphitobius diaperinus is an insect of the order Coleoptera, popularly known as birdwatcher, which adapt easily to the environment due to the availability of food and humidity present in the bed. They present great capacity for proliferation and resistance to conventional treatments, both chemical and mechanical, causing significant losses to the national poultry industry. Thus, the objective of this work was to evaluate the pathogenicity of a commercial formulation based on Metarhizium anisopliae on adults of A. diaperinus in vitro tests. For the biological tests, the insects were collected in an aviary located in the Municipality of Governador Mangabeira - BA, then were taken to the Laboratory of Parasitology of the Universidade Federal do Recôncavo da Bahia, where adult sexing was performed. In the experimental design, six groups were formed, each containing six experimental units, which contained five pairs each. For preparation of the fungal formulations the manufacturer's recommendations were followed, however, in the water used to suspend the conidia was added 0.01% Tween 20. This suspension was prepared using 100mL sterile distilled water, 4μL of Tween 20 and 5g of commercial formulation based on M. anisopliae. After this initial step, two aliquots of 30 mL this suspension were separated and soybean oil added at 5 and 10% concentrations. As controls were used a group containing only water and two containing solution of distilled water and 0.01% of Tween 20 added to vegetable oil at 5 and 10%. After the treatment, the plates were kept in a climatized lab oven type B.O.D. with controlled temperature and humidity (25°C ± 1°C and 80% ± 5% RH) and monitored every three days for 12 consecutive days in order to count for dead insects and fungal growth in arthropods. As a result it can be observed that all the groups that contained oil caused mortality in the insect right after the treatment, including the control groups with oil. Thus, it is possible to conclude that soybean oil presents lethality to A. diaperinus and the commercial formulation of Metarril without the addition of oil does not present a pathogenic action for this insect.