EFFECTS OF REFUGE CONTENT AND FOOD AVAILABILITY ON REFUGE-SEEKING BEHAVIOR IN CRYPTOLESTES-FERRUGINEUS (STEPHENS) (COLEOPTERA, CUCUJIDAE)

The effects of the contents of the refuge and the presence of food in the arena on refuge-seeking behaviour in two strains of Cryptolestes ferrugineus (Stephens) was investigated in the laboratory by confining adults in 21 cm dia arenas containing a central refuge. Some beetles were recorded in the refuges even when they contained only glass balls, although considerably fewer than when they contained whole wheat grains of flour. This suggests that a refuge retains some attraction for beetles even when food is absent, perhaps by providing physical contact around the insect's body. The addition of wheat or flour to the arena also reduced the numbers of beetles recorded in the refuges. Results were less clear-cut for a strain of C. ferrugineus that had been reared in the laboratory for over 25 yr than for a strain more recently obtained from the natural storage environment. These results are discussed in relation to the importance of insect behaviour in laboratory bioassays and control in grain stores.