Description and some biological aspects of Acarophenax dominicai n. sp. (Acari: Heterostigmata: Acarophenacidae), an egg parasite of lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)

Abstract

A new species of mite, Acarophenax dominicai was described and illustrated based on male and phoretic female. The new species was reported parasitizing of lesser grain borer, Rhyzopertha dominica (F.) eggs infested wheat grains. Adult females of this species most closely resemble those of Acarophenax lacunatus Cross and Krantz (1964). The new species is separable from A. lacunatus by its smaller size, ornamentations on dorsum and venter, the shape of tergite margins; aggenital plate; gnathosoma, as well as the chaetotaxy of legs I-IV. Holotype female and five paratype females; holotype male and four paratype males, were deposited in the Acari collection of Plant Protection Department, Faculty of Agriculture, Assiut University, Egypt. Some biological aspects are provided. Female mite produces one close d eggs capsule and remains alive until the capsule comes out. Female mites settle on the dorsum of host female during the pre-oviposition period, then leave the host in the period of oviposition and feed on egg’s contents. Male mites are ephemeral and may not emerge from the gravid-female. Mite sex ratios are highly skewed, with an average of 19.7 ± 0.3: 0.77 ± 0.23 females to males (mite progeny/eggs capsule/gravid-female). When females reach adulthood, mating take place either within the gravid-female (if present) or with a male which has previously emerged from another eggs capsule. Male mites are not parasitic and had poor locomotion abilities.