This article is part of our Organic Pest Control Series, which includes articles on attracting beneficial insects, controlling specific garden pests, and using organic pesticides.
Lacewing Flies (Chrysoperla rufilabris)
If your landscape includes numerous flowers and native shrubs and trees, you probably have beneficial lacewings in your garden. Several species may inhabit the same garden, including large and small green lacewings, and perhaps brown lacewings if your garden borders on woods.
Adult lacewing flies have light green or brown bodies one-half to 1 inch long, with finely veined transparent wings. Adult lacewings take to the air in the evening, seeking out scents given off by aphid honeydew or caterpillar frass. Female lacewings lay individual eggs near aphid colonies, or on leaves well-populated with other soft-bodied insects. Each egg is raised from the leaf surface by a slender stalk. Females can lay more than 400 eggs. Lacewing larvae feed for about a month, consuming about 600 aphids in that time. Because of their powerful hooked mandibles, lacewing larvae are often called aphid lions. Lacewings are common throughout North America. Multiple generations are common in warm climates.
What Do Lacewings Eat?aphidscabbage wormswhiteflies
How to Attract Lacewings
Tolerate light aphid outbreaks, because they are an important food source for lacewings and lady beetle larvae. Remove row covers from plants during the evening hours so lacewings can check them for pests. Do not use pesticides of any kind when lacewings are active. Grow a diversity of plants to provide shelter and good hunting conditions for lacewings. Should you notice an aphid problem that needs to be brought to the attention of lacewings, spray plants with a light solution of sugar and water (1 tablespoon sugar per cup of water). The sugar water simulates aphid honeydew, and can quickly increase visits by lacewings and lady beetles.
One type of green lacewing (Chrysoperla rufilabris) is available for purchase and release from numerous companies that sell beneficial insects. Like other beneficial insects you might introduce into your garden, green lacewings are most likely to be successful if a good food source is ready and waiting. They are especially helpful in greenhouses.
More information about lacewings is available from the University of California, Utah State University, and Fairfax County, Va., public schools.