Potential of Acarophenax lacunatus (Prostigmata: Acarophenacidae) as a biological control agent of Rhyzopertha dominica (Coleoptera: Bostrichidae) L.R.D'A. Faroni a , R.N.C. Guedes b, *, A.L. Matioli c a Departamento de Engenharia AgrõÂcola, Universidade Federal de Vic ° osa, Vic ° osa, MG 36571-000, Brazil b Departamento de Biologia Animal, Universidade Federal de Vic ° osa, Vic ° osa, MG 36571-000, Brazil c Departamento de Entomologia e Nematologia, Universidade Estadual de Sa Äo Paulo, Jaboticabal, SP 14870-000, Brazil Accepted 9 June 1999 Abstract A recent report of the parasitic mite species Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) attacking populations of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) led to the present investigation. Maximum female size and average number of progeny per female mite were assessed at eight dierent temperatures (ranging from 20 to 418C) and 60% r.h. using R. dominica as the host. The ability of the mite species to suppress eggs, ®rst instar larvae, and adults of R. dominica was assessed at 308C and 60% r.h. The largest female sizes of the mite and progeny numbers were obtained around 308C (259 mm and 17 ospring/female respectively) with minimum values obtained at the most extreme temperatures used in this study. Mite densities of at least four individuals per 500 ml jar containing 50 adults of R. dominica, resulted in almost complete suppression of eggs, ®rst instar larvae, and adults of the host species after 45 days. This same range of mite densities led to reductions of wheat weight losses of 15 and 25% after 45 and 60 days after infestation respectively. Acarophenax lacunatus shows good potential as a biological control agent of R. dominica. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Mites; Stored products; Wheat; Grain borer Journal of Stored Products Research 36 (2000) 55±63 0022-474X/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0022-474X(99)00027-2 www.elsevier.com/locate/jspr * Corresponding author Tel: +55-31-899-2006; telefax: +55-31-899-2537. E-mail address: guedes@mail.ufv.br (R.N.C. Guedes)