Phylum Arthropoda
Subphylum Hexapoda
Class Insecta
Order Neuroptera
Common names: lacewings, antlions
Overview
Neuroptera, or lacewings, are predatory, mostly delicate insects with, as their common name suggests, two pairs of lace-like wings with many intricate veins. Dusty lacewings (Coniopterygidae) have few veins and their bodies are covered with a waxy secretion. Moth lacewings (Ithonidae) have wings that are hairy along the margins and veins; they are moth-like in appearance. Lacewings have chewing (mandibulate) mouthparts; relatively large compound eyes; long segmented antennae, which may be clubbed at the tip in some species; a wingspan ranging from 5�150 mm; and a body up to 50 mm in length. Mantis flies (Mantispidae) have spiny raptorial forelegs similar to those of praying mantids (Mantodea). The larvae of lacewings, many of which are commonly known as antlions, look very different from the adults, being grub-like with large jaws projecting from the front of the head; the jaws are used to grasp prey.
Distribution and diversity
Worldwide about 5,000 described species of lacewings are found across a wide variety of habitats and climatic regions. In Australia lacewings are widespread, particularly in arid and semi-arid areas of the continent. Currently 551 species in 132 genera from 14 families are listed for the Australian fauna but it is estimated to comprise at least 800 species.
Life cycle
Sperm transfer in lacewings is direct and females usually lay their eggs on or in foliage, branches or bark. Many species lay their eggs at the end of thin stalks, which may be attached to wood, leaves or other surfaces such as the windows and walls of houses. After hatching the larvae moult 3�5 times, depending on the species. At maturity, the larvae spin a silken cocoon in which to pupate on vegetation or under bark. Larval development is usually rapid and some species have several generations each year, although other species in colder areas may take up to two years to develop fully.
Feeding
Lacewings are predatory as both adults and larvae, although adults of some species may supplement their diet with honeydew or pollen; a few feed exclusively on these fluids. They feed by piercing food with their elongate mandibles and maxillae that are connected to form a sucking tube. Adults mainly eat soft, sap-sucking insects such as aphids and scale insects (Hemiptera). Most larvae are active predators of small insects which they capture, then suck out their insides. In sandy soil, antlions sit in the base of the pits they construct; they catch small insects, particularly ants, that fall into the pit. Members of one group of Mantispidae are unusual in that the first instar larvae are parasitic on female spiders; later instars feed on the spider's eggs once the spider has laid them.
Ecology
Adult lacewings are mostly arboreal, found in trees and shrubs, but some are found on lower vegetation. They are common on native plants, such as flowering eucalypts, in suburban gardens and homes. Adults are solitary but may group together or swarm during mating. When disturbed they usually fly away or release a strong smelling liquid. They are active during the day or night; some are attracted to light. Because of their diet, some species are beneficial predators of plant-sucking insect pests in agricultural ecosystems. Mass rearing and release of members of Chrysopidae (green lacewings) have become important in the biological control of crop pests. Due to their well-known ecological requirements, lacewings have also been considered valuable indicator species for assessing the ecology of natural and semi-natural habitats.
Neuroptera, from Aireys, Victoriaa
Image credit: Photographer: Mark Harvey
� Western Australian Museum
