Green Lacewings are common insects in North America and Europe. In the order Neuroptera and family Chrysopidae, there are somewhere between 1,200 and 2,000 species (depending on the source). Adults measure 0.3–1.0 inches long (8 to 25 mm) long and are usually bright green to greenish-brown. Some have noticeable golden eyes. They’re primarily nocturnal, so look for them at night near your porch lights, where they’ll sometimes cling to your house. In the daytime, they usually rest on the underside of leaves. During their larval stage, they’re important predators of pest insects.
Chrysopidae
Have you noticed these long, slender insects at night, probably near your porch light? They’re adult Green Lacewings, delicate, harmless eaters of pollen and nectar. They can hear very well and when they hear a bat echolocating in search of insects to eat, they hide by closing their wings and dropping to the ground. As larvae, they’re called “aphid lions,” for good reason: at that stage of their lives, they’re insectivores.

Green lacewing eggs (Chrysoperla rufilabris) laid near aphids (Douglas Mills/Flickr; CC BY-NC-ND 2.0)
Green Lacewings lay tight clusters of eggs on stalks only 1/3-inch (8.4 mm) long, typically on the underside of a leaf on a plant that has aphids. That way, when they hatch, the larvae have a ready food supply. Some lacewing species lay eggs singly rather than together. Each egg is the size of a pinhead and the stalks are hair-thin and made of silk. Eggs darken when ready to hatch. You can buy Green Lacewing eggs for biological pest control.
Aphids and other small insects better hightail-it when they see a Green Lacewing larva coming! These critters not only look threatening, but they are. While their adult stage feeds on pollen, nectar, and honeydew (aphid excretions), their larvae are aggressive predators. Send a mental salute when you see one— it’s helping to control aphids, mealybugs, and other pest insects on your plants.
The larvae of some lacewing species keep themselves safe from birds by collecting debris on their bodies. If you see a tiny, messy mass of lint, sand, dirt, or other stuff purposefully moving about on a leaf, you’re watching a larva on the prowl.