Preferência alimentar da Rhyzopertha dominica (Coleoptera: Bostrichidae) por arroz e subprodutos

Abstract

Insect infestation in rice grain storage generates negative effects, both qualitative and quantitative. The objective of this work was to evaluate the food preference of Rhyzopertha dominica (Coleoptera, Bostrychidae) for rice with husk and its byproducts. The work was carried out at the Laboratório de Bromatologia e Nutrição Animal na Universidade Federal do Pampa – Campus Itaqui; from March 16 to 20, 2019. The methodology used was bioassays of food preference in a free choice test of R. dominica in adult stage by rice and the by-products of its processing. Samples of rice products and adult beetles were collected in an agro-industry in the municipality of Itaqui. The design used was completely randomized (DIC) with 6 treatments and 4 replications. The treatments consisted of healthy products (without infestation), being: Rice with Husk (AC), Canjicão (Ca), Rice Husk (CA), Rice Bran (FA), Rice rough (Q) and Control. The exposure of R. dominica from the point of release in the treatments offered indicates that the preference, with greater number of insects by the general average, for rice bran. In the Modular Arena, the number of insects was similar between rice bran and hominy. In the other treatment compartments, there was little incidence of insects and most of the insects remained at the Point of origin. This may be related to the way the insects adapted to the environment and to the greater number of insects in the rice bran treatment, which may be due to the beetle's resistance to opening galleries in the grain, making the location of the appropriate food. R. dominica has a food preference for rice bran to the detriment of Rice with Husk, Canjicão, Rice Husk and Rice rough.