Psoroptes ovis

Psoroptes
Kingdom	Animalia
Phylum	Arthropoda
Class	Arachnida
Sub-class	Acari
Order	Sarcoptiformes
Family	Psoroptidae
Genus	Psoroptes
Species	Psoroptes ovis

Also known as: Scab mite

Introduction

Psoroptes ovis are astigmatic, non-burrowing mites of the class Arachnida. They are around 750μm (0.75mm) in length, and oval shaped. They are extremely pruritic, and cause a contagious skin disease, Psoroptic Mange, as well as a loss in body condition. They also cause the host to rub and bite the infected areas, resulting in further trauma.

Predilection site: Skin; particularly on legs, feet, and the base of the tail.

This mite is found worldwide, but has been eradicated from Australia and New Zealand.

Hosts

Sheep, cattle, goats, horses, rabbits, and camelids.

Identification

The adult Psoroptes are around 0.75mm in length and oval in shape. They have three-jointed pedicles, each with suckers on the ends; also known as pulvilli.

The legs of adult females are all approximately the same length. However, in the males the fourth pair of legs is significantly shorter than the rest. The males also tend to be smaller then the females.

The males may also be identified via copulatory suckers and paired posterior lobes. The males attach to female tritonymphs, sometimes protonymphs, in a process called copula. The males then remain in copula until the females moult for the final time. Copulation then occurs.

Life Cycle

The life cycle is confined to the skin surface. The eggs are relatively large, and within around 2 days transform into a hexapod larva. The larvae then moult into a protonymph, which then subsequently moults into a tritonymph. Finally the tritonymph moults to become a mature adult.

Each stage takes around 2 days to complete. The total duration from egg to adult, takes around 10 days, but this figure can be longer. Adult female life expectancy is around one month and she lays 2-3 eggs per day, hence a mite population on an animal can expand rapidly.

Transmission is generally from direct contact with infected animals, such as at markets or in livestock transporters, but as the mite can survive off the host indirect transmission may also occur.

Psoroptes ovis Learning Resources
Vetstream To reach the Vetstream content, please select	Canis, Felis, Lapis or Equis
Literature Search Search for recent publications via CAB Abstract (CABI log in required)	Psoroptes ovis publications

WikiVet® Introduction - Help WikiVet - Report a Problem