Food preferences and the value of animal food for the carabid beetle Amara similata (Gyll.) (Col., Carabidae)
Fawki, Shams; Toft, S.;
Abstract
Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include animal food
in their diet to a considerable extent. We therefore hypothesized that the performance of these beetles would be
enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory
feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet
treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval
survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the
adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all
pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive
and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but
reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral
weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may
gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food.
Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
in their diet to a considerable extent. We therefore hypothesized that the performance of these beetles would be
enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory
feeding experiments with adults and larvae of Amara similata. Both adults and larvae were subjected to different diet
treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval
survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the
adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all
pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive
and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but
reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral
weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may
gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food.
Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.
Other data
Title | Food preferences and the value of animal food for the carabid beetle Amara similata (Gyll.) (Col., Carabidae) | Authors | Fawki, Shams ; Toft, S. | Keywords | carnivory, food quality, food specialization, granivory, ground beetle | Issue Date | 2005 | Journal | Journal of Applied Entomology | DOI | http://www.scopus.com/inward/record.url?eid=2-s2.0-28144437928&partnerID=MN8TOARS 10.1111/j.1439-0418.2005.00992.551-556 http://www.scopus.com/inward/record.url?eid=2-s2.0-28144437928&partnerID=MN8TOARS http://www.scopus.com/inward/record.url?eid=2-s2.0-28144437928&partnerID=MN8TOARS http://www.scopus.com/inward/record.url?eid=2-s2.0-28144437928&partnerID=MN8TOARS |
Scopus ID | 2-s2.0-28144437928 |
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