Parasitic Insects, Mites and Ticks: Genera of Medical and Veterinary Importance/Mites birdnests

Bird mites associated with nest of hosts

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Characters of nest mites of birds

These are large mites with powerful legs for active crawling. They rest and reproduce in the nest or housing of their hosts. From there they seek their host for a rapid blood meal, detach and return to the nest. Their behavior is nidicolous. Mouthparts are relatively large, with long chelicerae that are either retracted within body or extended. Palps are long, of five segments.

Photograph shows a live Dermanyssus bird mite that feeds on blood of poultry birds; dark color showing at posterior of mite is blood in gut of mite. Chelicerae are not extended. (Photograph by Gilles San Martin).

Diagram of feeding at skin represents a dermanyssid mite piercing skin of its host to obtain a blood-meal. Chelicerae are shown extended. (scales are not accurate).

Glossary

• Copulatory suckers = Some mites of various genera couple during mating using a pair of suckers on the female and corresponding knobs on the male (5 on Megninia).
• Dorsal plate = a sclerotized and symmetrically shaped area on dorsal surface of idiosoma (equivalent to scutum of Hard-ticks).
• Reticulated = Having a surface pattern of a network of fine lines (5 on Dermanyysus).
• Striated = Having a surface pattern of fine parallel lines, like a finger-print.

Dermanyssus (Dermanyssidae)

Characters: female, dorsal. 1- Body clearly divided into the anterior gnathosoma, and an oval posterior idiosoma. 2- Legs are long and end in paired claws with a pulvillus. 3- Palps are long and 5 segmented. 4- Chelicerae form a long piercing structure when fully extended from body. 5- Dorsal plate is large, approximately rectangular with a distinctly blunt posterior margin; its surface is reticulated, not striated. 6- Body and legs bear numerous long setae. 7- These mites are large, easily visible to unaided vision.

Hosts: Chickens and other poultry, caged and wild birds, are fed upon temporarily by Dermanyssus gallinae (Poultry red-mite). This species will feed on many species of mammal, including humans, if birds are not available. Workers in poultry houses are often bitten if infestations are allowed to build up .

Signs and disease: The mite cause irritation, anemia and biting-stress. Heavy infestations can accumulate in the structure of poultry houses, leading to serious loss of production.

Ornithonyssus (Macronyssidae)

Characters: female, dorsal. 1- Body clearly divided into anterior gnathosoma, and posterior idiosoma. 2- Palps are long and 5 segmented. 3- Chelicerae form a long piercing structure when fully extended from body. 4- Legs are long and end in paired claws with a pulvillus. 5- Dorsal plate is large, oval and with a distinctly pointed posterior margin; its surface is reticulated, not striated. 6- Body and legs bear numerous long stout setae. 7- These mites are large, easily visible to unaided vision.

Hosts: Ornithonyssus sylviarum (Northern fowl-mite) and O. bursa (Tropical fowl-mite) feed on chickens and other poultry, caged and wild birds. They will feed opportunistically on mammals including humans .

Signs: Irritation, restlessness, anemia, biting-stress are caused. Feathers develop a dirty matted appearance. Dermatitis and scabbing of skin occurs, especially around the vent.

Disease: Heavy infestations can accumulate in the structure of poultry houses, leading to serious loss of production. These mites may transmit to poultry the viruses causing Fowlpox, and Newcastle disease.

Megninia (Analgidae)

Characters: female ventral left, male ventral right. 1- Legs end in a pulvillus. 2- Legs bear small numbers of stout setae. 3- Apodemes of both sexes are distinct but those of first coxae are not joined. 4- Third legs of males are much larger than other legs. 5- Males have a pair of terminal lobes on their idiosoma and a pair of copulatory suckers. 6- Setae on body are few but all are stout and long.

Hosts: Megninia ginglymura is one example of many species of Feather-mites. These infest varied species of birds, including poultry, feeding superficially, at base of feathers.

Signs and disease: Depluming, damaged feathers, irritation, and dermatitis are typical signs. Heavy infestations decrease egg production .

Characters of Fur-mites of rodents

These are small mites with distinctive specialization of one or two pairs of legs adapted as large pincers to clasp onto hair of host. They spend their entire life-cycle on their host, where they feed parasitically on cutaneous tissues and liquids.

Myobia (Myobidae)

Characters: adult, dorsal. 1- Body profile is an irregular circle, with distinct lateral bulges. 2- Mouthparts are small. 3- First pair of legs is modified as clasping organs. 4- Legs 2 to 4 protrude from body margin and end in a single claw. 5- Dorsal surface of body bears sparse setae of various shapes. 6- A pair of long setae protrudes from posterior body margin.

Hosts: Myobia musculi infests the fur of laboratory and wild mice.

Signs and disease: Heavy infestations lead to dermatitis, harsh fur or alopecia, and pruritic biting-stress.

Myocoptes (Myocoptidae)

Characters: female, ventral. 1- Body profile is an irregular oval. 2- Mouthparts are well developed. 3- Legs 1 and 2 end in large pulvilli. 4- Legs 3 and 4 are modified as clasping organs. 5- A pair of long setae protrudes from posterior body margin. 6- Integument is striated (dorsally it bears 4 distinct pairs of setae). Also: profile of an egg is shown.

Hosts: Myocoptes musculinus infests the fur of laboratory and wild mice.

Signs and disease: Erythema, inflammation, dermatitis, and alopecia are typical signs. Pruritic biting-stress occurs when infestations are heavy.

Characters of taxonomically diverse non-parasitic mites that lead to allergies

These mites are free-living in all stages of their life-cycles. Some species feed on stored grain and hay. Other species feed on organic debris including flakes of dead skin from mammals in the same housing. The mites produce dust consisting of their dead bodies and fecal pellets. This dust readily forms airborne allergens. In confined housing this can result in various allergies to mammals, of most importance are dermatitis, rhinitis and asthma in horses, dogs, and humans. Acarus, Glycyphagus and Dermatophagoides are shown as examples of dust allergy mites. Other genera of importance are Tyrophagus and Pyemotes .

Acarus (Acaridae)

Characters: female ventral. 1- Legs are all long and end in a claw. 2- Body outline is oval. 3- Chelicerae of the mouthparts are well developed. 4- Apodemes of first legs are joined in a Y shape. 5- Integument surface is smooth, without striations, and setae are sparse.

Note: Acarus siro, the Flour-mite causes allergic, digestive and metabolic problems in domestic animals exposed to them as dust or in contaminated feedstuff.

Glycyphagus (Glycyphagidae)

Characters: female, ventral. 1- Body profile is oval; wider posteriorly. 2- Mouthparts are prominent, with well developed chelicerae and associated palps. 3- Legs are long and end in stalks with a pulvillus. 4- Apodemes of legs 1 are joined at their tips. 5- Integument is without striations but bears many long setae. 6- Some setae are complex with finer extensions.

Note: A typical dust allergy mite that feeds on grain is Glycyphagus domesticus (Grocer's-itch mite).

Dermatophagoides (Pyroglyphidae)

Characters: female, ventral. 1- Body profile is a regular oval. 2- Mouthparts are prominent, with well developed chelicerae and associated palps. 3- Legs are long, stout and end in a pulvillus. 4- Apodemes of legs 1 are not joined. 5- Integument is distinctly striated; it bears few setae. 6- Two pairs of long setae project from the posterior body margin.

Note: Dermatophagoides pteronyssinus and D. farinae (House-dust mites) are typical dust allergy mites that feed on organic debris and skin flakes. See photograph of House-dust mites at start of chapter Acarines - general characters.

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