Control of the Mupli Beetle,Luprops tristis(Coleoptera: Tenebrionidae), and Dormancy Phase-related Variation in Insecticide Susceptibility1

Abstract

Massive home invasions by the Mupli beetle, Luprops tristis F. (Coleoptera: Tenebrionidae), with the onset of monsoon rains, aggregation in a prolonged state of dormancy at specific locations, and repeated selection of the same locations for years provides an excellent opportunity to control the beetles employing suitable insecticides. The weak physical stature of the surviving beetles during the last phase of dormancy lead to the proposition that there were differences in insecticide susceptibility during the early- and late-dormancy phases. Hence, efficacy of three pyrethroid insecticides were tested with filter-paper bioassays to determine LC99 and KC99 values in the early and late phases of dormancy and to analyse whether the efficacy of the compounds vary between the early and late phases. During the late-dormancy phase, these compounds caused immediate knockdown but not immediate mortality at the lowest application rates. However, because the beetles have to be controlled during the early phase of dormancy when home invasions occur, the best control strategy for this nuisance pest is to knockdown the beetles and physically remove them instead of direct mortality.