Host egg preference by the parasitic mite Acarophenax lacunatus (Prostigmata: Acarophenacidae)

The potential of Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) as a biological control agent of Rhyzopertha dominica (F.) and the lack of information on the host range of this mite species led to the present investigation carried out in laboratory conditions. Petri dish arenas divided into four regions, each containing five potential host eggs [Dinoderus minutus (F.), Oryzaephilus surinamensis (L.), R. dominica and Tribolium castaneum (Herbst)], were used in the study. A single physogastric female mite was released in the centre of each arena and its progeny preference for each potential host species was recorded. There was a significant influence of time on the parasitism rate and there was no egg parasitism of O. surinamensis by A. lacunatus. In no-choice tests, female mites showed higher egg parasitism on R. dominica and D. minutus than on T. castaneum. In addition, female mites also showed significantly greater preference for R. dominica, followed by D. minutus, than for T castaneum in free-choice tests. These results suggest a broader host range of A. lacunatus than initially suspected and favour the possibility of its use as a biological control agent in integrated pest management programs in storage units. (C) 2002 Elsevier Science Ltd. All rights reserved.