Pyemotidae is a family of mostly parasitic

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

s that feed on the larvae and other developmental stages of various insects but some species are

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

fungivorous Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoebas, gastropods, nematodes, bacteria and othe ...

Characteristics

Members of this family are elongated, cylindrical mites with a large gap between the front two pairs of legs and the hind two pairs. The

chelicerae The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or similarly ...

(mouthparts) are needle-like. In females the body behind the posterior limbs becomes much enlarged when eggs are being carried.

Distribution

Members of this family have a widespread distribution and are found in most parts of the world.

Ecology

The adult female mites are mostly parasitic on insects. Their

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

range includes many

holometabolous Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago (or adult). Holometabolism is a synapomorphic trait of all insects in the superorder Endopterygot ...

insects such as honeybees, bark-boring beetles,

moths Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

and stored product pests. They parasitise various development stages of their host species but mostly it is the larvae which are attacked. They pierce the host with their chelicerae and suck out the

haemolymph Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...

. The female starts to breed after feeding on haemolymph. The eggs are retained inside the

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to a ...

(body) behind the two rear pairs of legs, and this part of the body becomes grossly swollen while the larvae complete their development inside. The males emerge first and feed by puncturing their mother's opisthosoma. They

copulate Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetr ...

with the new-borne females when they emerge; this stimulates the females to crawl away and find new hosts to parasitise. The genus '' Pyemotes'' includes species that attack bee and

bark beetle A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the ...

larvae; some of them are venomous, paralysing the larvae being attacked with their

saliva Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...

. One species ''

Pyemotes tritici ''Pyemotes tritici'' is a species of mite known as the grain itch mite or straw itch mite. It is a cosmopolitan species that is found on straw, hay and stored grain. It is a parasite of small arthropods and is being investigated as a possible bi ...

'' attacks the larvae of grain moths and stored grain pests and is known as the "straw itch mite" because when humans come into contact with it, it attempts to feed on their skin, injecting venomous saliva and causing an itchy red rash. Some members of the family are not parasitic, with other feeding methods being

herbivory A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

and fungivory. Some species are the vectors of

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

ic fungi.

References

{{Authority control Acariformes Acari families