Body size and nutrition intake effects on fecundity and overwintering success in Anchomenus dorsalis (Coleoptera: Carabidae).

Structural body size and adult feeding conditions seem to be important determinants of fitness in income breeding species. However, little is known about the relative importance of structural body size and nutritional state on fecundity and winter survival in carabids. In this study, two separate experiments were performed. The effects of the structural body size of females (expressed as the length of the elytra and the width of the pronotum) and the effect of starvation on the fecundity of the ground beetle Anchomenus dorsalis (Pontoppidan, 1763) were investigated in the "fecundity experiment." The influence of structural body size, feeding conditions (full, partial, or no feeding) before the winter, and behavior during the winter (burrowing into the substrate) on winter survival in A. dorsalis females were studied in the "overwintering experiment." Egg production was positively influenced by both the structural body size of females and adult feeding. The effect of structural body size on the number of eggs laid outweighed the effect of feeding. However, the total fecundity (the number of eggs laid plus the number of mature eggs in ovaries) were more strongly affected by feeding in comparison to the structural body size of females. Interestingly, there was no significant effect of structural body size, feeding before winter, or behavior during winter on the survival of A. dorsalis females during the winter. However, our overwintering results could be affected by extreme weather conditions throughout experimental season and by the experimental design, which is discussed in detail.