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by Rob Curtiss and Steven Booth, originally published 1993; revised online December 2007
Chrysoperla carnea (Stephens)
Chrysopa nigricornis Burmeister
Hemerobius humulinus Linnaeus
Hemerobius neadelphyus Gurney
Meleoma dolichartha (Navas)
Micromus variolosus Hagen
The lacewings listed here, and other less common species, are important natural enemies native to the Pacific Northwest. Green lacewings are widely distributed and are important generalist predators. They are often abundant in orchards where IPM is practiced and feed on a variety of insects. Although less well known, brown lacewings can also become abundant in orchards where soft pesticide programs are used. Lacewing larvae are active earlier in the season than many other predators and are good biological control agents for early season pests. Inundative releases of lacewings have been used to control mealybugs and variegated leafhoppers in California.
Both green and brown lacewing larvae prey mostly on aphids but also attack scale insects, mealybugs, leafhoppers, thrips, mites, pear psylla and many other small sedentary insects. Adults of Chrysopa nigricornis are also carnivorous, but adults of most species feed on aphid honeydew and plant fluids.
Life stages – Green lacewings
The egg is oval, green or white and is suspended on a long, hair-like stalk. The egg is about 1/50 inch (0.5 mm) long, while the stalk is about 1/4 inch long (6 mm). Eggs are laid singly or in groups.
The larva’s alligator-shaped body is yellow or mottled gray with red or brown and has clumps of bristles. Its prominent sickle-like mandibles, or jaws, are longer than the head and are used to capture the prey and extract the body juices. The larva develops through five instars and is about 2/3 inch (15 mm) long when mature.