The Cryptochetidae are a small family of tiny flies (generally 2 to 4 mm long). Some twenty to thirty species are known. Generally they are metallic blue black, stoutly built, with the head broad and high and with clear wings.McAlpine, J. F. et al (eds) Manual of Nearctic Diptera. Monographs No. 27 & No. 28 Biosystematics Research Institute, Ottawa. Ontario Research Branch. Pub: Agriculture Canada Vol 1 1981 & Vol 2 1987 Like other species in the superfamily Lonchaeoidea, the Cryptochetidae have antennae with a cleft in the second segment. Unlike practically all Schizophora however, they lack an arista, or if they do have one, it is too small to distinguish with any confidence. The family name refers to this unusual distinction; "Cryptochetidae" literally means "those with hidden bristles". The adult flies also are unusual among insects in that they have only a single pair of abdominal

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s — this is not a serious physiological challenge in such small insects. Again in resemblance to other Lonchaeoidea, the Cryptochetidae do not have more than one proclinate orbital bristle on each side. The

frons Insect morphology is the study and description of the physical form of insects. The terminology used to describe insects is similar to that used for other arthropods due to their shared evolutionary history. Three physical features separate insec ...

is densely setulose. The

costa Costa may refer to: Biology * Rib (Latin: ''costa''), in vertebrate anatomy * Costa (botany), the central strand of a plant leaf or thallus * Costa (coral), a stony rib, part of the skeleton of a coral * Costa (entomology), the leading edge of th ...

has a break at the end of the subcosta. The sixth abdominal

sternite The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the ...

in the male is symmetrical and it has an 8th

tergite A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...

. In the female the seventh tergite and sternite are fused, and the eighth segment is elongated. The larvae are of biological and economic interest, being endoparasitoids of coccids. In ''Cryptochetum iceryae'', which parasitizes ''

Icerya ''Icerya'' is a genus of scale insects in the family Monophlebidae. It is named after physician-naturalist Dr. Edmond Icery of British Mauritius. Hermaphroditism Hermaphroditism In reproductive biology, a hermaphrodite () is an organism ...

'', there are four larval instars. The first instar is sac-like and lacks both trophi and tracheae but at the caudal end it bears a pair of finger-like processes. The caudal end of the digestive tract is closed. During subsequent

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

s the caudal processes grow longer and become filamentous; in the final instar they are much longer than the whole body. These filaments probably are respiratory organs. Only a few species of Cryptochetidae have been described, and most of those occur in tropical countries. At one time they were allocated to the

Agromyzidae The Agromyzidae are a family commonly referred to as the leaf-miner flies, for the feeding habits of their larvae, most of which are leaf miners on various plants. A worldwide family of roughly 2,500 species, they are small, some with wing leng ...

but now are regarded as a separate family.

Genera

These three genera belong to the family Cryptochetidae: *'' Cryptochetum'' Rondani, 1875 *'' Librella'' McAlpine, 1976 *'' Phanerochaetum'' Hennig, 1965

References

Brachycera families Taxa named by Charles Thomas Brues Taxa named by Axel Leonard Melander {{Acalyptratae-stub