Leg impairment affects the reproductive attributes of a ladybird, Menochilus sexmaculatus (Fabricius)

Abstract

Abstract Natural injuries and their causes have recently garnered attention amongst researchers, however the effects of these injuries on life history traits are still sparsely investigated. In the few studies that have been conducted injuries are known to have a debilitating effect on male virility and reproductive performance. Thus the effect of leg injuries in males on mating behaviour and reproductive output in the ladybird beetle, Menochilus sexmaculatus was investigated. This is the first study on the effect of injury on any life history trait in Coccinellidae. The legs of the male were amputated at three different joints on the same side and opposite sides for one leg or two legs. These amputated males were paired with uninjured females and the mating behaviour and subsequent reproductive output was observed. Time to commence mating, latent period and mating duration in impaired males were observed and were all found to be higher than that of uninjured males. Fecundity and percent egg viability were reduced in all impaired male pairs. Males with physical disability were found to copulate for an extended duration, perhaps to ensure maximum paternity.