Potential of Acarophenax lacunatus (Prostigmata : Acarophenacidae) as a biological control agent of Rhyzopertha dominica (Coleoptera : Bostrichidae)

A recent report of the parasitic mite species Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) attacking populations of Rhyzope rtha dominica (F.) (Coleoptera: Bostrichidae) led to the present investigat ion. Maximum female size and average number of progeny per female mite were assessed at eight different temperatures (ranging from 20 to 41 degrees C) and 60% r.h. using R. dominica as the host. The ability of the mite specie s to suppress eggs, first instar larvae, and adults of R. dominica was asse ssed at 30 degrees C and 60% r.h. The largest female sizes of the mite and progeny numbers were obtained around 30 degrees C (259 mu m and 17 offsprin g/female respectively) with minimum values obtained at the most extreme tem peratures used in this study. Mite densities of at least four individuals p er 500 mi jar containing 50 adults of R. dominica, resulted in almost compl ete suppression of eggs, first instar larvae, and adults of the host specie s after 45 days. This same range of mite densities led to reductions of whe at weight losses of 15 and 25% after 45 and 60 days after infestation respe ctively. Acarophenax lacunatus shows good potential as a biological control agent of R. dominica. (C) 2000 Elsevier Science Ltd. All rights reserved.