Evaluation of maize genotypes on oviposition preference of Diabrotica speciosa (Germar)

Abstract

Diabrotica speciosa (Germar) is a pest of economic importance for several crops in South and Central America, causing damage to plants in both the larval and adult stages. This study aimed to develop methodologies for evaluating the oviposition preference of D. speciosa for maize genotypes. Plants were grown in a greenhouse and brought to the laboratory to perform the experiments. We evaluated (i) the ability of D. speciosa to recognize the most suitable maize oviposition host; (ii) the optimal number of D. speciosa pairs per maize plant; (iii) the preferred plant age for oviposition; (iv) the effect of adult feeding resource on oviposition and survival; and (v) the oviposition preference of D. speciosa on maize genotypes selected from previous studies. D. speciosa females were able to identify the presence of a maize plant for oviposition, compared to a substrate without a plant. However, females were unable to discern the best host plant for the development and survival of their offspring when different maize genotypes were assessed. The presence of bean plants (Phaseolus vulgaris L.) as an additional food source increased the number of eggs laid by D. speciosa. Conversely, the absence of bean plants resulted in higher adult mortality in the experiments. Additionally, this study showed that maize genotypes with antibiosis characteristics do not always manifest in repellence or deterrence of oviposition. There may be no correlation between antibiosis and oviposition preference in the interaction between D. speciosa and maize plants.