Susceptibility of Four Different Sorghum Varieties to Infestation by the Khapra Beetle

Abstract

In this study, we evaluated the susceptibility of four different sorghum varieties to infestation by the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), as compared with wheat, which served as a 'control' commodity. In population growth assays, there was preference for population development on wheat compared to the different sorghum varieties. In contrast, there were no significant differences in total population development among the four varieties of sorghum. However, the proportion of immature stages (larvae, pupae) in relation to the adult stage varied significantly among the different varieties. Moreover, significant differences were noted among the commodities tested regarding the final weight decrease, as well as the amount of frass and kernel damage. Our study clearly demonstrates noticeable differences in the susceptibility of the varieties to T. granarium infestation. These results show that this species can develop on different varieties of sorghum, and variety selection should be further considered in a host-plant resistance-based management program for T. granarium.

Keywords: Trogoderma granarium; grain damage; population growth; quarantine species; sorghum; varietal resistance.