Worldwide in most temperate climates
Flying mostly in the evening, adult lacewings have finely veined, transparent wings over one-half to 1-inch long (1-2.5 cm) greenish brown bodies. Lacewing eggs are also quite distinctive, because the elongated white eggs are borne on thin hairs attached to leaves or stems. Where you see lacewing eggs, you will almost always find a colony of aphids, scale, or other small sucking insects nearby, because the young larvae of these pests are the primary food source for lacewing larvae. Adult lacewings find the aphids by smelling the honeydew they excrete as they feed.
Lacewing larvae are huge eaters of aphids. During their month-long feeding period, a single slender brown lacewing larva will consume more than 500 aphids. Aphids are vectors for several plant viruses and other diseases, so the fewer there are in the garden, the better.
Food and Habitat:
Lacewings feed on pollen and nectar from flowers, as well as aphid honeydew. The adults of some species attack and eat small insects. Lacewings often are quite active in the foliage of trees and shrubs, and many species pass winter as dormant pupae buried in undisturbed soil.
Tolerate small aphid outbreaks in spring to help support a thriving summer population of lacewings. Do not use insecticidal soaps or other natural pesticides on plants where lacewing eggs are present. Landscapes that include a diversity of shrubs, trees, and garden plants are often well endowed with lacewings.