Life‐cycle stage morphology of Psoroptes mange mites

Abstract

Detailed life-cycle stage descriptions for the ectoparasitic mite Psoroptes ovis (Hering) (Acari: Psoroptidae) from rabbit hosts (syn. Psoroptes cuniculi) are presented. The results resolve a number of contradictions in the literature relating to the recognition of the life cycle stages of these mites. This study supports the view that there are two distinct male nymphal stages, both lacking dorsoposterior tubercles. The male tritonymph is significantly larger than the protonymph and has five pairs of metapodosomal setae rather than three. In addition, male tritonymphs have two pairs of cuticular pits on the central metapodosoma rather than the single pair of the protonymph. The results also show that the female protonymph can be distinguished from the male nymphal stages and the female tritonymph. Both female nymphal stages possess dorsoposterior tubercles, but the protonymph is significantly smaller than the tritonymph. In addition, the protonymph possesses three pairs of metapodosomal setae rather than five, one pair of cuticular pits rather than two, and a pulvillus on leg IV which is absent in the female tritonymph. The presence of dorsoposterior tubercles enables the female nymphs to be distinguished easily from the males. By contrast, distinguishing between the nymphal stages of the same sex relies on the identification of both the number of metapodosomal setae and cuticular pits. These descriptions are used to produce a key, which allows the various stages of both sexes to be distinguished.

Clinical Studies on the Efficacy of Different Topical Drugs with Ivermectin Injection in the Treatment of Egyptian Water Buffalo Calves Infested with Psoroptes Spp. Mites

“…Samples were brought to the laboratory and examined microscopically according to Soulsby, (1983). The parasite identified according to the characters showed by Sanders et al, (2000). The severity of infestation was graded from mild to moderate and severe according to the results of clinical examination that focus on pruritus, alopecia, scales, erythema and abrasion degree.…”

Os parasitas de ovinos

“…Apresenta cinco estádios em seu ciclo de vida: ovo; larva (com três pares de patas), dois estádios de ninfa (protoninfa e tritoninfa) e finalmente machos e fêmeas adultos. As ninfas e os adultos apresentam quatro pares de patas (Sanders et al, 2000).…”

Relationship between Psoroptes cuniculi and the Internal Bacterium Serratia marcescens

“…In rabbits the mite causes intense pruritus with the formation of crusts and scabs, that in the untreated animals can completely fill the external ear canal and the internal surface of the pinna (Bates 1999). Some recent studies indicate that P. ovis, the cause of sheep scab, and P. cuniculi could be phenotypic variants of the same species (Zahler et al 1998;Bates 1999;Sanders et al 2000).…”