Aspectos biológicos e suscetibilidade a nematoides entomopatogênicos de Mycotretus apicalis Lacordaire, 1842 (Coleoptera: Erotylidae), praga de Pleurotus sajor-caju

Abstract

Mycotretus apicalis species is commonly found in greenhouse Pleurotus sajor-caju production in Lavras, MG. Studies related to biology, rearing techniques, damage analysis and control of this species have not been done so far. Thus, this study aimed to evaluate both, the biological aspects of M. apicalis on Pleurotus sajor-caju mushrooms, and its control using entomopathogenic nematodes. Regarding the potential of the species as insect pest, we can conclude that the injuries caused by these insects reduce the commercial value of the mushroom, which causes economic losses. The biological data indicate that the M. apicalis species has four larval instars. The period egg-adult was about 22 days and the average longevity of adults was 89,7 ± 32,89 days. The net reproductive rate (Ro), the intrinsic rate of increase (Rm) and the finite rate of increase (λ) were 230.78; 1.69 and 5.46, respectively. The mean generation time (T) was three weeks. The rearing methodology using dried P. sajor-caju mushrooms was ideal for the maintenance of the insect in laboratory. Steinernema nematodes were more pathogenic to M. apicalis larvae than Heterorhabditis nematodes. The estimated concentrations of 168 and 158 infective juveniles/larva for S. anomali and Heterorhabditis sp. Ijaci, respectively, were significant for mortality of M. apicalis larvae, but not significant for mortality of pupae. These results indicate a high potential of these nematodes to be used for control of Erotylidae in P. sajor-caju mushrooms cultivation.