Consequences of successive mating in the ladybird beetle, Cheilomenes sexmaculata (Coccinellidae: Coleoptera).

Multiple mating is common across insects. Both males and females mate multiply to enhance their reproductive fitness. However, repeated matings may incur several physiological costs including a prolonged refractory period where individuals lose their ability to remate for a period of time. The present study aimed to evaluate the potential costs associated with successive matings in a ladybird beetle, Cheilomenes sexmaculata. Unmated males and females of C. sexmaculata were given three successive matings with different unmated partners. Unmated females mated without any mating interval with unmated males of the similar age group, whereas males were tested under two conditions: no interval between matings (no-gap) and a 24-hour gap between matings. The effect of successive mating was assessed on the sperm allocation (volume transferred to females), mating parameters and area and perimeter of males’ seminal vesicles. We also tested for the presence of a refractory period in this ladybird beetle. The results revealed that males of C. sexmaculata transferred a consistent amount of sperm across successive matings, while females showed increased sperm storage. Successive matings did not affect mating latency or latent period, though copulation duration declined in males mating without intervals. Mating status had no effect on seminal vesicle dimensions, and no refractory period was observed in either sex. These findings demonstrate the high mating capacity and reproductive resilience of C. sexmaculata, indicating minimal physiological costs of successive matings. Such efficiency supports its suitability for large-scale rearing and sustained performance as an effective biological control agent.