What Bug Is That? The guide to Australian insect families.

Logo: What Bug Is That? Logo: Taxonomy Research & Information Network



Adults are found most commonly on trees and shrubs, but a few species are more characteristic of low vegetation. All are predators, and are typically very cryptic insects: many drop and feign death if disturbed. They may live for several months, during which females lay up to several hundred elongate eggs attached by their sides to vegetation (up to about 2500 eggs have been recorded in a non-Australian species). The chorion is often lightly sculptured, and eggs may hatch in a few days or overwinter. The fusiform larvae are active predators, and do not carry debris. They usually have only short body hairs, and the head in some is retracted into the thorax. Hemerobiid larvae differ from those of Chrysopidae by having the tarsal empodium trumpet shaped only in the 1st instar. The apex of the abdomen, as in some other arboreal lacewing families, is used to 'hold on' during locomotion. The larval period is several weeks, and the prepupa and pupa occur in a (usually) loosely woven silk cocoon on vegetation or under bark. This is the major overwintering stage in northern temperate species. Many of those undergo 1-3 relatively discrete generations each year.


Brown lacewings are small, delicate, often pale species, with fore wing length 5-12 mm. Antennal scape usually enlarged and moniliform antennae often nearly as long as fore wing. Wings usually subequal but some species of Notiobiella have the hind wing reduced. Several non-Australian hemerobiids have it reduced to a small stub, and the fore wing short and thickened: such species are undoubtedly flightless. A Holarctic species, Psectra diptera , is dimorphic, with the wings either normal or considerably shortened. A frenulum type of wing coupling is normally present in macropterous forms, and the presence or absence of a recurrent humeral vein in the fore wing separates two groups of genera. When that vein is present the wings are usually broad and held relatively flat when the insect is at rest. When it is absent, wings are long and narrow and held vertically. Trichosors are usually distinct.


The family is of world-wide distribution. Australian species (New 1988) represent about 12 genera, and appear to be most numerous in the east. Many species are rare, and only 2 can be regarded as generally common. The slender-winged Micromus tasmaniae is abundant, especially throughout the temperate parts of the country, and is often common feeding on aphids on cereals or other crops, and Drepanacra binocula has broad, slightly falcate fore wings which are very variable in pattern. Both species occur also in New Zealand, but most other Australian species are apparently endemic or shared with New Guinea. Carobius (9 spp.) contains several attractively mottled species; Notiobiella (4 spp.) contains broad-winged forms and one of the few green hemerobiids ( Notiobiella viridis ). Some Zachobiella (3 spp.) are minute and narrow-winged. The otherwise widespread Hemerobius is represented in Australia by only one rare species.

  • Hemerobiidae larvae

  • Drepanacra binocular

  • Micromus tasmaniae

  • Notiobiella viridis

  • Zachobiella pallida