T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Lacewing (Brown) Wesmaelius subnebulosus

Domain: Eukaryotic
Kingdom: Animalia
Phylum: Arthropoda
Tribe: Hexapoda
Class: Insecta
Order: Neuroptera
Family: Hemerobiidae (Brown Lacewings)
Genus: Wesmaelius
Species: W. subnebulosus
Scientific name: Wesmaelius subnebulosus
Synonyms: Boriomyia maorica, Boriomyia subnebulosa, Boriomyia subnebulosa melancholica, Hemerobius fuscus, Hemerobius subnebulosus, Hemerobius subnebulosus lucidus, Hemerobius subnebulosus obscurus, Kimminsia subnebulosa, Subboriomyia fusca, Wesmaelius subnebulosus lucidus, Wesmaelius subnebulosus melancholicus, Wesmaelius subnebulosus obscurus,
Common name: Brown lacewing

Wesmaelius subnebulosus are 12 mm long, soft-bodied insects with four membranous wings and brown bodies. The wings can be varied in pattern and colour. Their wing venation has forked costal cross veins and dark spots.
Adults fly predominately at night and are drawn to lights.
Females lay tiny, non-stalked, oblong eggs on their side onto plant tissues. The eggs hatch in about 4 days after being laid and larvae developing through three instars before pupating. The larvae are creamy-brown with dark reddish-brown stripes and spots and they move their heads from side to side when walking. Their bodies are flattened, tapered at the tail, have distinct legs and prominent mandibles to grasp their prey.
Lacewing pupation occurs in loosely woven, spherical, silken cocoons attached to plants or under loose bark. Adults emerge in early spring and disperse. Breeding continues throughout the summer.
Both larval and adult stages of W. subnebulosus are predacious. They are aphidophagous predators though other soft bodies insects are also prey.
This species have a low temperature threshold which give them a survival advantage during cold spells and frosts in temperate climates.





Lacewing larvae are beneficial insects and are voracious predators capable of feeding on small caterpillars and beetles, as well as aphids and other insects. They are a light brown and have a large pair of hooked jaws sticking out from the front of the head. They drive their jaws into soft-bodied insects or eggs before sucking up the contents.
Brown lacewing, nymph about 5mm long