Studies viewing the improvement of the rearing methodology of Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) in laboratory were carried out. Larval development was compared in three rearing methods, two of which with natural diet using corn seedlings kept on vermiculite or on germination paper sheets and a third system using artificial diet. The following biological parameters were evaluated: duration and viability of the larva-adult period; weight of newly emerged adults (male and female); duration of pre-oviposition and oviposition periods; male and female longevity and fecundity. The development of the insect under different larval densities (100, 200, 400 and 600 larvae), using the same amount of natural diet, (corn seedlings) was also evaluated. When the insects were reared on corn kept in wet vermiculite the viability of the larva-adult period was higher than when corn was kept on wet paper sheet; the opposite was observed with the length of the developmental period. Females reared in artificial diet had lesser pre-oviposition and oviposition periods and laid less eggs than those reared in natural diet. The increase in the larval density extended the duration of the immature phases, decreased the viability of the larva-adult period and reduced the weight of adults. The rearing technique of D. speciosa using natural diet in vermiculite provided a large amount of insects, with a significant reduction in labor and laboratory space.
Insecta; rootworm; larva-adult viability; fecundity; longevity
