The effect of behaviour on the survival of Cryptolestes ferrugineus in an insecticide-treated laboratory environment

The effect of refuge-seeking behaviour on the survival of two insecticide resistant (malathion-specific) and two susceptible strains of Cryptolestes ferrugineus (Stephens) in laboratory arenas treated with insecticide was determined. Insect mortalities were reduced significantly when artificial refuges were present in arenas treated with either fenitrothion or malathion. The strain exhibiting the highest degree of refuge-seeking behaviour also had the highest survival rates in treated arenas. In arenas treated with fenitrothion, refuge-seeking behaviour increased at a high dose (250 mg/m(2)) compared to a lower dose (2 mg/m(2)). More beetles were found in refuges on arenas treated with fenitrothion than in refuges on untreated arenas; however, no such difference was observed in malathion-treated arenas. fenitrothion-treated arenas, most beetles died in the refuges but when arenas were treated with malathion, more beetles died in the arenas than in the refuges. The implications of these results for pest control are examined. (C) 1997 Elsevier Science Ltd.