You may be familiar with green lacewings, those delicate fliers that prey on aphids and other garden pests. This column focuses on another member of the Neuroptera order, an equally voracious aphid eater that gets far less attention: the brown lacewing.
Brown lacewings make up the Hemerobiidae family. For an insect that maxes out at about a centimeter long, it’s got an impressive resume.
Lest you think all lacewings are the same, brown lacewings may be more closely related to mantidflies (look them up, they’re fantastic!) than to green lacewings, which are in the Chrysopidae family. Fossils of Hemerobiidae date back to the Jurassic period, whereas green lacewings only date back to the following period, the Cretaceous.
To confuse matters, as entomology often does, brown lacewings can be green, and green lacewings can be brown. Some green lacewings even become brown as they get older. The surest way to tell the difference is to take a deep dive into the pattern of veins on their wings … but generally, if a lacewing is very small and brown, it’s a Hemerobiidae.
Brown lacewing larvae look a little like lady beetle larvae. They’re long, segmented and thin, tapering at the head and tail, and have wide, U shaped jaws and six legs. Both larvae and adults are predators. There are at least 28 genera and 500 species of brown lacewings.
I’ve seen adult Hemerobiidae nearly year-round. According to the first reference site below, females of one species (Hemerobius pacificus) which is found in California and Washington, but strangely, not yet found in Oregon, lay 600-700 eggs, and a full generation can take place in just six weeks during summer months.
Stay curious!
See more of Karen’s work here.
Sources:
Excellent Hemerobiidae page from the University of California: https://ipm.ucanr.edu/natural-enemies/brown-lacewings/#gsc.tab=0. Accessed 4/29/26.
Nice photos of adult and larva: https://entomology.ces.ncsu.edu/biological-control-information-center/beneficial-predators/brown-lacewing/. Accessed 4/29/26.
All photos by Karen Richards.