The susceptibility of soya bean meal to infestation by some storage insects

Abstract

Twenty-four species were tested on soya bean meal at 70% r.h. and at either 20°C, 25°C or 30°C. Those species that completed development at 25°C or 30°C were also tested at 20°C. Some species were also tested at 50 and 80% r.h. The following species were able to complete development from adult to adult at near optimum temperature and relative humidity conditions: Ahasverus advena, Cryptolestes ferrugineus, Ephestia cautella, Ephestia elutella, Lasioderma serricorne, Plodia interpunctella, Ptinus tectus, Stegobium paniceum, Tinea columbariella, Tineola bisselliella, Tribolium castaneum and Trogoderma granarium. A further five species were able to reach the adult stage when cultures were set up with half grown larvae, but failed to complete a second generation on soya bean meal: Attagenus pellio, Dermestes ater, Dermestes frischii, Dermestes lardarius, Tenebroides mauritanicus. Mould developed on all food at 80% r.h. and to a lesser extent at 70% r.h. This may have affected development of some species. Judging from the number of adult progeny and the development period, the species most likely to attack stored soya bean meal in temperate climates were Stegobium paniceum, Ptinus tectus, Tineola bisselliella, Ephestia cautella and Lasioderma serricorne. In heated premises and warmer climates Trogoderma granarium, Tribolium castaneum, Ahasverus advena, Lasioderma serricorne, Ephestia cautella and Plodia interpunctella might become a nuisance in this commodity. Ephestia elutella was able to develop at the relatively low moisture content of 8.8% wet weight, and so also might be troublesome in warmer conditions. The markedly different performances of congeneric species of Tribolium, Tenebrio, and Ephestia are discussed, and possible reasons for the failure of certain other species are suggested.