Effect of egg cannibalism on mating preferences and reproductive fitness of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae)

Abstract

• Mate preferences are plastic in nature and changes with changing environment and mates’ internal conditions. • Non-cannibalistic adults were preferred over cannibalistic adults as mates. • Time to commence mating lasted less for homogeneous diet pairs than heterogeneous diet pairs. • Longer copulation duration and higher fecundity were recorded for non-cannibal pairs. • Egg viability and total developmental durations of offspring were similar for all mating pairs. Cannibalism has been reported in a large proportion of coccinellids in fields as well as in laboratories but studies involving mate preferences and potential benefits of cannibalism on reproduction in Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae) have yet not been done. Thus, we assessed the effect of conspecific egg cannibalism on mate preferences and reproductive outputs including offspring development. Higher mate preferences were recorded for non-cannibalistic mates (fed on A. craccivora ) than cannibalistic ones (fed on conspecific eggs). Mating parameters were significantly influenced by cannibalism. Time to commence mating lasted less for homogeneous diet pairs than heterogeneous diet pairs. Longer copulation duration and higher fecundity were recorded when one of the individuals in mating pair or both was a non-cannibal. Egg viability did not differ significantly in all the reciprocal crosses. In addition, the total developmental durations of offspring were similar for all mating pairs.