OBSERVATION OF EPIGEIC PREDATORS AND PREDATION ON ARTIFICIAL PREY IN A CEREAL FIELD

Predation activity of different epigeic predators on artificially supp lied prey was studied in a cereal field during several 24 h periods fr om spring to early summer 1993. Carabids were the most frequently obse rved predators. Among them Poecilus cupreus was the most voracious spe cies during day-time, and Agonum muelleri during night-time. Predation rates were highest between 10.00 and 18.00 h and lowest between 02.00 and 10.00 h. Linear regressions showed significantly positive relatio ns between temperature and predation rates, and between predation and activity density of epigeic predators. The latter relation was stronge r when only activity density of predators which were observed to consu me baits was included. Quadrat sampling and pitfall sampling showed th at with the former only a small proportion of bait-consuming predators were caught whereas with the latter method this proportion was high.