Atratividade e desenvolvimento de Hypothenemus hampei (Coleoptera: Curculionidae) a prebióticos isolados e associados a Beauveria bassiana (Bals.) Vuill.

Abstract

The coffee berry borer Hypothenemus hampei (Ferrari) is considered the main pest insect of coffee culture, causing great damage to national and world coffee production. More efficient and sustainable control strategies are still needed in the management of the coffee berry borer. The use of prebiotic compounds can help to increase the efficiency of biological control with Beauveria bassiana by causing both an attractive effect to insects and a nutritive substrate for better development of the entomopathogenic fungus. This work evaluated whether the application of yeast-based fermented prebiotics, alone or associated with B. bassiana have effects on the attractiveness, survival and development of H. hampei. The first experiment was conducted in the field in two experimental areas to evaluate the attractiveness of the coffee berry borer to two prebiotics (Preb1 and Preb2) used alone in traps in comparison with methanol:ethanol (1:1) and water (control). The second experiment consisted in a preference bioassay with chance of choice, in laboratory, to evaluate the influence of the association of B. bassiana with prebiotics in the choice and colonization of fruits by H. hampei, recording the number of insects perforating the fruits in 24h, and the number of holes and insects inside the fruits after 48h. The third experiment consisted of a no-choice bioassay in the laboratory, evaluating the survival of colonizing females and the development of progeny in coffee fruits treated with B. bassiana alone or associated with prebiotics. As main results, in the first experiment there were greater collections of the coffee berry borer with the methanol:ethanol cairomonium in relation to the control and prebiotics in all evaluations. In the second experiment, there was a preference of H. hampei females for fruits treated with B. bassiana, B. bassiana + Preb1 and B. bassiana + Preb2 in relation to the control. In the third experiment, adult survival was significantly higher in the control compared to treatments with B. bassiana, B. bassiana + Preb1 and B. bassiana + Preb2. It can be concluded that prebiotics isolated in field traps are not attractive to adults of H. hampei; there is no phage-stimulating effect of prebiotics to increase the preference of fruits treated with B. bassiana and in the control efficiency; B. bassiana is efficient in the control of colonizing females and in the reduction of progeny production when applied alone or associated with the prebiotics.