Insect friend or foe? Brown insect with triangular head and tent-like wings

Nicolle Ritchie<ritchi67@msu.edu>, Michigan State University Extension - June 25, 2026

Several brown lacewings have been spotted this year already. Are they agricultural friends, foes or something in-between?

cream colored cloth with a brown bug on it — Brown lacewings appeared early in alfalfa and forages and are now in other field crops. Photo by Nicolle Ritchie, MSU Extension.

Only relatively few insects are economic agricultural pests out of the millions of insects in the world. But what are less familiar insects doing out in the fields? Are they benefiting us, causing harm or neither?

I’ve seen several brown lacewings this year already, many more than I usually find in field crops. They appeared early in alfalfa and forages and are now in other field crops. You may have heard of or seen green lacewings, which are like the brown ones, that are beneficial predators of aphids and soft-bodied larvae.

Green lacewing vs brown lacewing adult — Green lacewings (left) are larger than brown lacewings (right). Brown lacewings have branched or forked veins along the wing edge, whereas green lacewings do not. Both are beneficial predators of nuisance insects. Photo by Nicolle Ritchie, MSU Extension.

Brown lacewing adults are identifiable by their brown colored bodies and clear wings held tent-like over the body. There may be dark spots or markings on parts of the wings. If you are able to get close enough to see the lacewing’s veins, they fork or branch near the edge of the wing. Larvae are dark and narrow with their posterior coming to a clear point, like a skinny alligator. They have prominent curved mandibles that stick out in front of their head.

Brown lacewing larvae are small, dark and slender with a tapering posterior. Photo by Katja Schulz CC BY 2.0. Photo by Nicolle Ritchie, MSU Extension.

Lacewing larvae and adults feed on aphids, caterpillars and other insects. Field crops growers may be pleased to know that lacewings will feed on western bean cutworm eggs. Verdict: friend.

two photos of lacewing larvae eating other bugs and eggs — Lacewing larvae feeding on a plant bug in wheat (left) and western bean cutworm eggs in corn (right). Photos by Chris DiFonzo, MSU Extension field crops entomologist.

You can preserve brown lacewings by avoiding broad-spectrum insecticides and only applying chemical controls when pests are at the treatment threshold. For insect pest scouting and threshold guidelines in field crops, refer to the Insect pest management guide.

For more pictures and details, check out the Michigan State University (MSU) Extension profiles on lacewings.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).