FACTORS AFFECTING THE REFUGE-SEEKING BEHAVIOR OF CRYPTOLESTES-FERRUGINEUS (STEPHENS) (COLEOPTERA, CUCUJIDAE)

The effects of insect sex, density and age on the refuge-seeking behaviour of Cryptolestes ferrugineus (Stephens) were studied by confining adults of several strains in 21 cm dia arenas containing a refuge filled with wheat. Refuge-seeking behaviour was greater in females than males, both in tests where the sexes were kept separate and also when they were mixed in equal numbers. Although more beetles were present in the refuges as density increased, a higher percentage of beetles was recorded in refuges by the end of the 2 week test period at a density of 25 adults/arena than at a density of 150 adults/arena. Similarly, more 0-3 wk old adults were found in refuges than adults aged 10-12 wk and 16-18 wk old. These results are discussed in relation to the known biology of this stored grain pest. © 1990.