__NOTOC__ ''Knemidokoptes pilae'' is a

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

which parasitises the

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, grasping, and holding (in probing for food, eating, manipulating and ...

s of psittacines, particularly

budgerigar The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet, shell parakeet or budgie ( ), is a small, long-tailed, seed-eating parrot native to Australia. Naturally the species is green and yellow with black, scallop ...

s, causing a

mange Mange () is a type of skin disease caused by parasitic mites. Because various species of mites also infect plants, birds and reptiles, the term "mange", or colloquially "the mange", suggesting poor condition of the skin and fur due to the infecti ...

known as ' scaly face'.Dwight D. Bowman and Jay R. Georgi, ''Georgi's Parasitology for Veterinarians'', 9th ed. St. Louis, Missouri: Saunders/Elsevier, 2009,
p. 67

Morphology

''K. pilae'' are roundish-oval mites. The males are up to 220 μm long and about 150 μm wide, females up to 356 μm long and about 300 μm wide. The four pairs of legs are short and stubby in shape and have five segments. At the ends of the extremities, males have unjointed grippers and suckers, while females have claws.

Life

''K. pilae'' lives off the substance of the beak, which it dissolves by means of a

keratinase Keratinases are proteolytic enzymes that digest keratin. They hold industrial promise, as they can turn keratin-rich farm waste such as feather meal into more digestible fragments. History They were initially classified as 'proteinases of unk ...

. They live primarily in the

cere The beak, bill, or Rostrum (anatomy), rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, wikt:grasp#Verb, grasping, and holding (in wikt:probe ...

and at the base of the beak of the infected birds. They inhabit a single host throughout their life cycle; infection of new hosts occurs by contact. The

viviparous In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juve ...

females drill tunnels in the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

where they give birth to six-legged

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e, which develop through two eight-legged

nymph A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

al stages from the second of which the adults molt.

Morphology

Life

References

Further reading