The prey spectrum of larval and adult Cantharis species in arable land: An electrophoretic approach

摘要

An electrophoretic approach was used in the present study to analyse the prey spectrum of L6 larvae and adults of Cantharis fusca L., C livida L. and C rustica Fallen. Evaluation of different electrophoretic separation methods and staining protocols showed that prey detection was possible with gradient gels and phosphoglucose isomerase (PGI) and esterase (EST) staining. The electrophoretic analysis of 454 larvae and 275 adults provided the following results: (i) 13 % of all electrophorized larvae contained prey enzymes, consumption of earthworms and dipteran or lepidopteran larvae was found in 9 % and 4 %, respectively. (ii) No enzymes of slugs, Tipulidae larvae or Enchytraeidae were found in the enzyme profiles of the larvae. (iii) Only 2.5 % of the adult individuals showed unidentified non-Cantharis enzymes, which suggests that predation on invertebrates is low under natural conditions. These results indicate that earthworms, soft-tissued insects and their larvae represent a major component in the prey of Cantharis larvae. Besides some predation on invertebrates, adult beetles probably feed mainly on nectar, pollen and honeydew.