ATIVIDADE INSETICIDA DE PLANTAS MEDICINAIS SOBRE O Callosobruchus maculatus (COLEOPTERA: BRUCHIDAE)

Abstract

This study aimed to evaluate the insecticidal activity of eight medicinal plants on Callosobruchus maculatus (F.) (Coleoptera: Bruchidae). Plant powder from Rosmarinus officinalis (L.) leaves, Peumus boldus (Mol) leaves, Matricaria chamomilla (L.) flowers, Baccharis trimera (Less.) leaves, Camellia sinensis (L.) leaves, Thea sinensis (L.) leaves, Ilex paraguariensis (St. Hil.) leaves, and fruits of Pimpinella anisum (L.) were used in the experiment. Bioassays were carried out under constant conditions of temperature (28±2 °C), relative humidity (70±5%) and scotophase of 24 hours. Experimental units consisted of 20 grams of cowpea (Vigna unguiculata (L.) Walp.) grains with 13% wet basis moisture content, 2 g plant powder and ten adult insects, both placed in plastic containers (60 mm in diameter x 60 mm high). The analyzed variables included: insect mortality, oviposition (egg number) and instantaneous rate of population growth (ri). The number of dead insects was recorded 5 days after bioassays were started, the egg number was recorded after 12 days, and ri was estimated on the 60th day. All the tested plants had toxicity to C. maculatus. The highest mortality was found in insects treated with P. boldus and I. paraguariensis. Number of eggs and ri also varied significantly among the powders. The lowest mean values for these parameters were recorded in the plots treated with P. boldus, P. anisum and R. officinalis.