Long adult life spain and polyphagy of a carabid beetle, Leptocarabus kumagaii in relation to reproduction and survival

Summary The reproductive patterns of two different age classes of Leptocarabus kumagaii adults, i.e. young beetles which were in the first year of adult stage and old ones which survived for more than two years, were studied in the field. The numbers of eggs laid were compared between young and old females and the effects of food quality and quantity were studied on egg production and maintenance in the laboratory. Both of the young and old beetles reproduced in the field population. The number of eggs laid did not significantly differ between the two. The number of eggs laid by female increased with an increase in the amount of miced beef eaten. Plant materials were ineffective for egg production but sufficient for the survival of both male and female beetles. The two life historical aspects, i.e. repeated reproduction and polyphagy were discussed in relation to environmental fluctuation and limitation of food resources.