Effect of Food and Mating on Longevity and Egg Production in the Green June Beetle (Coleoptera: Scarabaeidae)

Abstract

A laboratory rearing experiment was conducted to determine the effect of food intake and mating on longevity and egg production of the female adult green June beetle, Cotinis nitida (L.). A positive relationship existed between the number of eggs laid per beetle and beetle longevity (r = 0.37; P < 0.0001), where apple-fed beetles laid 2.2 eggs per day during a lifespan of 23.0 days and the water-fed beetles laid 1.87 eggs per day during a significantly shorter lifespan of 14.8 days (P < 0.0001). After mean adjustments for the effects of beetle longevity (by the LSMEANS procedure), the apple-fed beetles laid an average of 50.8 eggs which was significantly higher than the 26.9 eggs laid by the water-fed beetles (P < 0.0002). The number of matings had no effect on the numbers of eggs produced nor on beetle longevity. The treatment effects on percentage egg hatch by mating and feeding were insignificant. However, the effect of mating on the percentage of egg hatch differed depending on feeding. These differences were presumed to be due to soil differences between egg rearing containers and not to the effects of mating or feeding. These results suggest that feeding beetles live longer and produce more offspring than beetles that do not feed.