Acarology Lecture Notes PDF

Acarology “516 ZOO” Lecture 4&5&6 Dr. Osama B Mohammed & Dr. Jawahir ALGhamdi 1 The Sarcoptiformes (Astigmata) are a large group of relatively similar mites. Sub-order SARCOPTIFORMES They are all weakly sclerotised; stigmata and tracheae are absent, and respiration occurs directly through the cuticl...

Acarology “516 ZOO” Lecture 4&5&6 Dr. Osama B Mohammed & Dr. Jawahir ALGhamdi 1 The Sarcoptiformes (Astigmata) are a large group of relatively similar mites. Sub-order SARCOPTIFORMES They are all weakly sclerotised; stigmata and tracheae are absent, and respiration occurs directly through the cuticle. (ASTIGMATA) The order includes the families Sarcoptidae, Psoroptoidae and Knemidocoptidae, which are of major veterinary importance because they contain the most common mite species which cause mange and scab. Species of several other families may be important ectoparasites, and species of the Cytoditidae and Laminosioptidae live in the respiratory tracts and muscles of birds and mammals. 2 3 These are burrowing astigmatic mites with circular bodies flattened ventrally and the cuticle covered with fine striations. Family SARCOPTIDAE 4 Family PSOROPTIDAE ▪ These are oval-bodied, nonburrowing, astigmatic mites. ▪ The legs are longer than those of the burrowing mites, and the third and fourth pairs of legs are usually visible from above. ▪ Males have a pair of copulatory suckers, which engage the copulatory tubicles of the female. ▪ The three genera of veterinary importance are Psoroptes, Chorioptes and Otodectes. 5 Family KNEMIDOCOPTIDAE Twelve species of the genus Knemidocoptes (Neocnemidocoptes) have been described, of which three are of veterinary importance to poultry and domestic birds. 6 Family LISTEROPHERIDAE ▪ These are parasites of fur-bearing mammals with a distinct dorsal shield and mouthparts and legs modified. ▪ The genus of veterinary interest is Mycoptes. Myocoptes musculinus (A) 7 Family CYTODITIDAE ▪ Members of the genus Cytodites are respiratory parasites of birds, rodents, and bats. ▪ They are found in the respiratory system, lungs and air sacs of chickens, turkeys, canaries and a range of wild birds. ▪ The chelicerae are absent, and the palps fused to form a sucking organ. ▪ In Birds “Air sac mite” and causes granulomatous pneumonia. 8 Family LAMINOSIOPTIDAE Laminosioptes are relatively small mites with a smooth, elongated body and a few setae, affecting the muscles of chickens, turkeys, geese, partridges, pigeons, and wild Phasianidae. 9 Family ANALGIDAE Feather mites of the genus Megninia are found on down and contour feathers of chicken and other captive Galliformes. https://www.veterinaryparasitology.com/megninia.html 10 Family ATOPOMELIDAE Chirodiscoides is found on the fur of guinea pigs. 11 Family DERMOGLYPHIDAE Members of the genus Dermoglyphus are found on the quills of chickens and cage birds. 12 Family FREYANITIDAE Members of the genus Freyana are found on the quills of chickens and cage birds, particularly the feathers of turkeys. 13 Family EPIDERMOPTIDAE ▪ Bird ked mites depluming mange. cause ▪ The genera of interest are Epidermoptes, found on chickens. ▪ Microlichus found on quail. ▪ Promyialges found on passeriform cage and aviary birds. 14 Family PTEROLICHIDAE The two genera of veterinary significance are: 1.Pterolichus, found on the tail and flight feathers of chickens. 2. Sideroferus, found on the budgerigar. 15 (a) Micrograph of hypopi of Hypodectes propus from a southern crowned pigeon (bar 5 200 m m). (b) Ultramicrophotograph showing anterior end (bar 5 50 m m). Family HYPODERIDAE The genus Hypodectes is of importance in pigeons, doves, and other wild and captive birds. 16 Sub-order TROMBIDIFORMES (PROSTIGMATA) The trombidiformes (Prostigmata) are large and diverse mites in various forms and occupy different ecological habitats. Prostigmatic mites usually have stigmata, which open on the gnathosoma or the anterior part of the idiosoma, known as the propodosoma. There are over 50 families, of which four contain species of veterinary importance: Demodicidae, Cheyletiellidae, Trombiculidae and Psorergatidae. Other families may be of lesser importance, not as parasites but because of the allergic responses they induce. 17 Family DEMODECIDAE The Demodecidae is a family of prostigmatid mites, containing a single genus of veterinary interest, Demoof which are found in a wide range of animals including humans. These are small mites with an elongated ‘cigar-shaped’ body and four pairs of ‘stumpy’ short legs, located at the front of the body, in the adult. 18 Species of the genus Demodex are specialized mites that live in the hair follicles and sebaceous glands of a wide range of wild and domestic animals, including humans. They are believed to form a group of closely related sibling species, which are highly specific to hosts. Demodex phylloides (pig), Demodex canis (dog), Demodex bovis (cattle), Demodex equi (horse), Demodex musculi (mouse), Demodex ratti (rat), Demodex caviae (guinea pig), Demodex cati (cat) and Demodex folliculorum and Demodex brevis on humans. 19 Family CHEYLETIDAE ▪ The majority of mites in this family are predatory. ▪ Still, several species of mites of the genus Cheyletiella are of veterinary and medical importance as ectoparasites of dogs, cats, or rabbits that may transfer to humans. ▪ The mite’s body, up to 0.4 mm long, has a ‘waist’ and the palps are greatly enlarged, giving the appearance of an extra pair of legs. ▪ The legs terminate in ‘combs’ instead of claws or suckers. 20 Family TROMBICULIDAE ▪ Mites of the family Trombiculidae are parasitic only at the larval stage, the nymphs and adults being free-living. ▪ There are two common genera: 1. Neotrombicula, the ‘harvest mite’, which has a wide distribution in the Old World. 2. Eutrombicula, which occurs in North and South America, and whose larvae are known as ‘chiggers’. ▪ Both of these genera will parasitize any animal, including man. Other lesser genera include Leptotrombidium, a vector of scrub typhus (tsutsugamushi fever) in the Far East and Neoschongastia, affecting chickens, quail and turkeys in North and Central America. 21 Family PSORERGATIDAE Two species of the genus Psorergates are found on cattle and sheep; the species found on sheep is a major ectoparasite in southern hemisphere countries. The body is almost circular with the legs arranged equidistant around the body circumference, with two pairs of elongate posterior setae in the female adult mite, and single pairs in the male. The femur of each leg bears a large inwardly directed curved spine. 22 Family PYEMOTIDAE These are ‘forage’ mites found on hay and grain predating largely on insect larvae, but they can cause dermatitis on animals and humans. Mites of the genus, Pyemotes, are small mites with elongated bodies, the female mites giving birth to fully formed adults. 23 Family MYOBIDAE ▪ These are small blood-feeding mites found on rodents, bats, and insectivores. ▪ Species of the genera Myobia and Radfordia may cause a mild dermatitis of laboratory mice and rats respectively. 24 Family SYRINGOPHILIDAE Poultry quill mites, Syringophilus, feed on tissue fluids of feather follicles, causing feather loss. Family OPHIOPTIDAE These mites are found beneath the scales of snakes. 25 Family CLOACARIDAE These are mites found in the cloacal mucosa of reptiles. Cloacarus are found in aquatic terrapins (small turtles). Family PTERYGOSOMATIDAE These are parasites of lizards including the genera Geckobiella, Hirstiella, Ixodiderma, Pimeliaphilus, Scapothrix and Zonurobia. 26 Thanks.. 27