Please refer also to the following link for details on this group:
Coniopterygidae = Link 1
Description & Statistics
Both adults and immatures feed on small, relatively inactive prey such as coccids, mites and aphids. They are mainly found on shrubs and trees, although some species seem to be confined to low vegetation. Adults are active fliers especially at sunset, when both sexes are attracted to lights. Fontenellea maroccana Carp. & Lest. attacks Orthesia in North Africa and an undetermined species was observed feeding on Cryptoparlatoria leucaspis Lind. on cryptomeria in Japan (T. Ishii cited by Clausen, 1940). Withycombe (1923, 1924a) found several species to be predaceous on Phylloxera, his observations indicating that the feeding range of the various species is wide. Conwentzia psociformis Curt. is associated with oak in England where it feeds on Phylloxera but also on diaspine Coccidae, red mites, etc (Arrow 1917).
Eggs are laid singly on infested foliage. They are oval in outline, flattened dorsoventrally, and slightly pointed at the micropylar end. The chorion surface bears reticulate markings. Eggs of C. hageni Banks are yellowish-pink, although some may have an orange tint (Quayle 1913). Conwentzia psociformis lays a total of ca. 200 eggs.
The number of larval instars was noted as 4 for C. hageni (Quayle 1913). Larvae of this species feed on all stages of red mites, the body contents being entirely sucked out from a single puncture. One larva consumed 226 red mites during its feeding period. The oval, flattened cocoons of Conwentzia are usually found on the underside of leaves or on bark. They consist of a double layer of silk with loosely woven margins. Cocoons of Semidalis aleyrodiformis Steph. do not have a clear double layer of silk. Withycombe (1923, 1924a) found that the pupal skin is often left within the cocoon rather than discarded after adult emergence.
The life cycle of C. hageni is 37-43 days in summer, of which the egg, larval and cocoon stages cover 6-8, 18-22 and 13 days, respectively. Semidalis aleyrodiformis overwinters as mature larvae within the cocoon, while a portion of the adults of the first brood of C. psociformis persist in sheltered spots until the following springtime (Clausen 1940/62).
Although playing an active role in the natural control of orchard and tree pests, they have not been used successfully in biological control. However, an attempt was made in 1924 to establish Conwentzia psociformis Curt. in New Zealand to combat Phylloxera.
This is a cosmopolitan family with more than 100 known species. They may be identified by their tiny size; forewing, 2-5 mm; wing venation reduced; wings, often legs, and basal portions of antennae covered with a whitish or grayish, powdery wax secreted by glands situated on the head, thorax and abdomen. The antennae are short, beady and segmented, and ocelli are lacking.
Further Description & Ecology
The adults of this family are unlike other net-winged insects. With their small size - wingspan is between 1.8 and 5 millimetres - and their translucent brownish wings usually covered with the namesake whitish dust of waxy scales, they are at the first glance more similar to whiteflies (Aleyrodidae) which are true bugs and thus among the Pterygota not at all closely related to net-winged insects. A distinguishing feature is that like many other Neuroptera, dustywings carry their wings nearly side-by-side when at rest, whereas whiteflies carry them almost flat across the back. There are no more than two veins across the costal field and few cross-veins in general - unique among the living net-winged insects, dustywings do not actually have the "net-winged" venation. Some Coniopterygidae, like the genus Conwentzia, have only vestigial hindwings; others, like Helicoconis females, are completely wingless.
These insects are associated with woody plants, on and around which they usually spend their entire lives. Females depost their eggs singly on bark or leaves. Dustywing larvae are around 3.5 mm long. Their mouthparts consist of short, straight sucking tubes covered by the labrum (upper "lip"). They are crepuscular and dwell on shrubs and trees, where they feed on small invertebrates like scale insects, aphids and mites, as well as on arthropod eggs; the mouth tubes are used for sucking fluids from the prey. There are usually two generations each year.
Due to the dustywings' many apomorphies, the superfamily Coniopterygoidea was formerly believed to be monotypic, and the primitive traits of their larvae were held to evidence a quite basal place among the net-winged insects. But in fact the spongillaflies (Sisyridae), formerly allied with the Osmylidae in error due to their larvae's convergent morphology, seem to be close relatives of the Coniopterygidae, more plesiomorphic altogether as adults but with a number of peculiar and highly divergent apomorphies, particularly in the larvae. So even though the spongillaflies are not generally placed in the Coniopterygoidea as of yet, they most likely form a clade with the dustywings and thus it would seem that the Coniopterygoidea, rather than being maintained as an unnecessarily monotypic taxon, are better expanded to signify that the spongillaflies and the dustywings are each other's closest relatives among the net-winged insects. This is all the more significant because in this apparent clade, there would be a highly interesting and exactly opposing pattern of evolution - primitive larvae and highly advanced adults in the dustywings, versus primitive adults and very advanced larvae in the spongillaflies.
Numerous fossil taxa are known from the Late Jurassic onwards. Most of these, as well as a number of living genera, are of basal or uncertain position in this group's phylogeny.
Banks, N. 1906. A revision of the nearctic Coniopterygidae. Proc. Ent. Soc. Wash. 8(3-4): 77-86.
Cole, F. R. 1969. The Flies of Western North America. Univ. Calif. Press, Berkeley & Los Angeles. 693 p.
Engel, Michael S. & Grimaldi, David A. (2007): The neuropterid fauna of Dominican and Mexican amber (Neuropterida, Megaloptera, Neuroptera). American Museum Novitates 3587: 1-58.
Meinander, M. 1972. A revision of the family Coniopterygidae (Planipennia). Acta. Zool. Fennica 136: 1-357.