Susceptibilidade do besouro rola-bosta africano a reguladores de crescimento de insetos / Susceptibility of African dung beetle to insect growth regulators

Verificou-se a ação dos reguladores de crescimento de insetos (IGR), diflubenzuron e methoprene, sobre o besouro rola-bosta africano, Digitonthophagus gazella (Fabricius), um inimigo natural da mosca-dos-chifres, Haematobia irritans irritans (Linnaeus). Casais de besouros foram colocados em baldes contendo terra úmida e alimentados com fezes bovinas contendo 1, 0,5 ou 0,2ppm de diflubenzuron e 0,2ppm de methoprene. Os insetos e sua prole foram recuperados com o auxílio de armadilhas pitfall. Diflubenzuron e methoprene não afetaram a sobrevivência dos adultos inicialmente expostos, mas interferiram na produção de descendentes. Diflubenzuron, nas concentrações de 1 e 0,5ppm, também afetou a duração do ciclo de vida dos besouros. Nenhum dos IGRs alterou a razão sexual dos descendentes obtidos. As concentrações testadas de diflubenzuron mostraram-se moderadamente nocivas ao besouro enquanto methoprene a 0,2ppm mostrou ser pouco nocivo, segundo os critérios da International Organization for Biological Control.

The effects of insect growth regulators (IGR), diflubenzuron and methoprene, on African dung beetle, Digitonthophagus gazella (Fabricius), a natural enemy of the horn fly, Haematobia irritans irritans (Linnaeus), was studied. Beetles were placed in buckets partially filled with humid soil and were fed bovine feces containing 1, 0.5, or 0.2ppm diflubenzuron and 0.2ppm methoprene. Insects and their progenies were recovered by pitfall traps. Diflubenzuron and methoprene did not affect the survival of the adults but reduced their progenies. Diflubenzuron 1 and 0.5ppm also affected the life cicle of the beetles. None of the IGR modified the gender ratio of the progenies. According to the IOBC criteria, diflubenzuron tested concentrations showed to be moderately harmful to the beetles, whereas methoprene 0.2ppm was slightly harmful.

Cytotoxic evaluation of certain insect growth regulators and insect sex pheromones in cho-k1 cells

The cytotoxic effects of Diflubeizuron, pyriproxifen as insect growth regulators, ZZ/ZE-7,11-hexadecadienyl acetate, Z-9- hexadecenal and Z-11-hexadecenal as insect sex pheromones were evaluated in vitro using Chinese hamster ovary [CHO-K1] cells. Total cellular protein [TCP] content and methyl tetrazolium [MTT] assays were carried out using serum free medium and medium supplemented with fetal calf serum [FCS, 10%], bovine serum albumin [BSA, 1%] and/or metabolic activation system [S9-mix]. All the tested compounds displayed cytotoxic effects that rise with time exposure. TCP assay exhibited higher sensitivity than MTT assay with all the tested compounds. In presence of the added extracellular proteins and/or metabolic activation system [S9-mix], the cytotoxic effects significantly decreased which indicate that the tested agents may be binding non-specifically with protein and extensive metabolized to less toxic metabolites