Food-, temperature- and crowding-mediated laboratory dispersal of Carcinops pumilio (Erichson) (Coleoptera: Histeridae), a predator of house fly (Diptera: Muscidae) eggs and larvae
The dispersal potential of natural enemies is critical to the success of biological control by mass releases. In this paper the effects of satiation level, temperature and crowding on the dispersal of the house fly predator, Carcinops pumilio (Erichson), was studied under laboratory conditions. Adults with access to sufficient prey were reluctant to disperse and no flight dispersal was observed after 11 days of starving, which could be associated with depletion in energy reserves. Dispersion was less pronounced at 20°C than at 30°C A crowding level of 50 C. pumilio adults per 200 ml container resulted in the least dispersal and did not exceed 2.5 % per day compared with up to 24 % dispersal at a crowding level of 400 per 200 ml. The absence of food, increase in temperature and overcrowding, in any interaction, could be the driving force to initiate dispersal in C. pumilio. No significant sexual differences were found in the effects of the different parameters (food, temperature and crowding) on dispersal.