Identification: Similar to Green Lacewings (Chrysopidae). Brown lacewings are smaller, wings more rounded and somewhat hairy at wing edges. Veins at wing edges are more numerous and branched.
Size: 6-15 mm
Life Cycle: Females lay between 30 to 40 eggs (not stalked like Green Lacewings), singly on leaves, twigs or bark. Both adults and larvae eat smaller insects, particularly aphids and mealy bugs. Liquid food is drawn up through mandibles on larvae. Adults have chewing mouth parts. Larvae do not cover themselves with aphid debris, like Green lacewings. Short larval period from 12 to 24 days with 3 instars, the 3 being the longest and sometimes lasting 3 weeks. Several broods lasting from spring to fall. Cocoon structures are net-like, see-through rounded domes. Green lacewing cocoon are white and solid.
Seventeen species of Brown Lacewings are listed for Ontario. Over half of them are extremely rare and northern.
The common species in southern Ontario (7):
Hemerobius humulinus – Striped Brown Lacewing
Northern Ontario species (10):
Hemerobius conjunctus – Sudbury, Ottawa and north
Hemerobius costalis – Dryden and north
Hemerobius dorsatus – Hudson Bay
Hemerobius simulans – Type specimen from Hudson Bay (report of 1 in Ottawa & Niagara)
Megalomus angulatus – Sudbury and north
Megalomus fidelis – Sudbury and north
Micromus angulatus – Ottawa
Wesmaelius longifrons – Ottawa area, Georgian Bay and north
Wesmaelius nervosus – unknown. Present in B.C. Lectotype from New Hampshire
Wesmaelius subnebulosus – Belleville (eastern Ontario).