Biology, Reproductive Capacity, and Foliar Consumption of Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) in Different Host Plants

Abstract

Diabrotica speciosa is considered one of the most important agricultural pests in Latin America. Attacks various plant species including fructiferous, vegetable, cucurbit, dicotyledonous, and gramineous crops. The goal of this work was to evaluate the influence of different host plants, offered during the larval and adult stages of D. speciosa on their development, reproductive capacity, and foliar consumption. The insects were reared with corn in the larval stage and offered common bean, corn, soybean, forage turnip and wheat in the adult phase. In another essay, the larvae were reared with bean, soybean, forage turnip, corn, wheat, potato and adult stage offered only leaves of common beans to the insects. The insects reared with corn and fed on common bean leaves in the adult phase produced bigger numbers of eggs in contrast to the insects fed on other host plants. The longevity of adult specimens and the oviposition period were greater when adults of D. speciosa were fed on soybean, forage turnip, and common bean leaves, but these parameters were reduced in the insects fed on corn and wheat leaves. The viability of D. speciosa during the immature stage was greater when the larvae were fed with potato tubers or corn seedlings. However, the larvae reared on potato tubers exhibited a longer development period in contrast to larvae fed on other plants. In the foliar consumption tests, common bean leaves were preferred by adult of D. speciosa in contrast to other plants (soybean, corn and forage turnip) offered under free-choice conditions. On the other hand, in confinement conditions, common bean was preferred by insects when compared to turnip or corn leaves. The results showed that corn was the best food for the larval development of D. speciosa while common bean represented the most suitable host for the adults.