The extent of regeneration is impacted by the stage of amputation in ladybird beetles: a case study in Cheilomenes sexmaculata

Abstract

Regeneration is a topic of interest for centuries and arthropods are no exception. Trade-offs associated with regeneration are likely to indicate the reallocation of resources from other metabolic activities such as growth, development, or reproduction to regrowth of the lost body part. This may confer negative selection to some of the developmental traits of the organism despite regeneration being overall advantageous. Our hypothesis for the study was that the extent of regeneration and trade-offs associated with it may be stage-specific. To test this hypothesis, the right forelimb of all four larval stages of the ladybird beetle (Cheilomenes sexmaculata) was amputated. The amputated stages were reared till adulthood and all developmental transitions were recorded. Leg size was measured and compared with control. The result showed that the regenerated legs of all the treatments were smaller than the control and the regenerative potency of early larval stage was higher than late larval stages. Regeneration causes delay in post-amputation duration in all the treatments, increasing their total development period. However, insignificant difference was observed between the fresh body weight of regenerated and control adults. The length of unamputated left foreleg was reduced in regenerated beetles, showing some internal trade-off.