ROLE OF GRANIVORY AND INSECTIVORY IN THE LIFE-CYCLE OF THE CARABID BEETLE AMARA-SIMILATA

1. The cereal field carabid beetle Amara similata was selected to eluc idate the role of seeds and insects as food sources. Three experiments were performed to rank different weed seeds and insects in terms of f ood value: (i) fecundity in relation to adult diet, (ii) larval surviv al in relation to diet and (iii) larval survival in relation to parent al diet. 2. Seeds were found to be of high value and insects of low va lue both for adults and larvae. Adding insects to a seed diet gave no significant improvement. The value of single species of seeds varied w ithin adults and larvae, but also between adults and larvae. This is t he first report that Amara larvae are granivorous. 3. The value of dif ferent insects varied by species. Cereal aphid species were of the low est value both for adult and larval beetles. On a diet of mixed insect s, the adults were able to produce a low number of eggs but the larvae all died before pupation. 4. There was no simple relation between sur vival of the larvae and the quality of the parents' diet.