Eur. J. Entomol. 100: 531-544, 2003 ISSN 1210-5759 Ground beetles (Carabidae) as seed predators Al o is HONEK1, Zd e n k a MARTINKOVA1 and Vo jt e c h JAROSIK2 'Research Institute of Crop Production, Dmovská 507, CZ 16106 Prague 6 - Ruzyně, Czech Republic; e-mail:
[email protected] ;
[email protected] 2Faculty of Science, Charles University, Vinicná 7, CZ 120 00 Prague 2, Czech Republic;
[email protected] Key words. Carabidae, seed, predation, herb, weed, preference, consumption, abundance, crop, season Abstract. The consumption and preferences of polyphagous ground beetles (Coleoptera: Carabidae) for the seeds of herbaceous plants was determined. The seeds were stuck into plasticine in small tin trays and exposed to beetle predation on surface of the ground. In the laboratory the effect of carabid (species, satiation) and seed (species, size) on the intensity of seed predation was investigated. The consumption of the generally preferredCirsium arvense seed by 23 species of common carabids increased with body size. Seed ofCapsella bursa-pastoris was preferred by small carabids and their consumption rates were not related to their size. The average daily consumption of all the carabid species tested (0.33 mg seeds . mg body mass-1 . day-1) was essentially the same for both kinds of seed. Because of satiation the consumption of seed C.of arvense providedad libitum to Pseudoophonus rufipes decreased over a period of 9 days to 1/3—1/4 of the initial consumption rate. PreferencesP. of rufipes (body mass 29.6 mg) andHarpalus afifiinis (13.4 mg) for the seeds of 64 species of herbaceous plants were determined.