Green Lacewings: the Aphid Lions Patrolling Your Garden
By Paul Smith, pemdasgarden.com
Few garden allies work as hard — or look as unlikely — as the green lacewing. The adult is a floating green jewel with golden eyes and wings like fine lace. Its larva is a mottled brown "alligator" with sickle jaws that earned the nickname aphid lion: a single larva can eat hundreds of aphids in its lifetime, according to University of Minnesota Extension. Lacewings are almost certainly already patrolling your beds — this guide shows you how to recognize every life stage, invite more of them in, and avoid accidentally wiping them out. It is part of our beneficial insects garden guide, the hub for every helper in this cluster.
Meet the three life stages
Lacewings pass through four stages — egg, larva, pupa, adult — but you will mostly meet three of them. Learn all three, because each one is easy to misidentify.
The adult: a green jewel with lacy wings
The adult green lacewing is about 3/4 inch long, soft light green, with four long, finely net-veined wings folded like a tent over its slender body, thread-like antennae, and striking golden eyes (University of Kentucky Entfact-708; UMN Extension). Adults are weak, fluttery fliers, often noticed near porch lights on summer nights or hovering around aphid colonies.
Here is the surprise: the adult is not the hunter. Most adult green lacewings feed on nectar, pollen, and honeydew — the sweet excretion aphids leave on leaves — rather than on insects (UKY; South Dakota State Extension). A few lacewing species have predatory adults, but for the common green lacewings in home gardens, think of the adult as the scout and egg-layer, not the soldier. If your leaves are sticky with honeydew, lacewing adults may already be visiting for a drink.
The eggs: tiny balloons on stalks
Lacewing eggs are unmistakable once you know the trick: each whitish, oval egg sits alone at the tip of a slender, hair-like stalk about 1/2 inch long, laid singly or in small groups close to an aphid colony (UKY; UNH Extension). The stalk is believed to keep newly hatched siblings from eating one another before they disperse.
A cluster of pale dots on hair-thin stalks looks most like lacewing eggs — but spider egg clusters or even fungal threads can look similar at a glance, so confirm with a hand lens before deciding what you are looking at. When in doubt, leave them alone: destroying unidentified eggs is how gardens lose their free pest control.
The larva: the aphid lion
This is the stage that does the damage — to pests. The larva is a flattened, mottled brown-and-cream creature up to about 1/2 inch long that looks like a tiny alligator, armed with a pair of large, curved, hollow jaws it uses to pierce soft-bodied prey and drain the body fluids (UKY; UMN). It passes through three feeding stages (instars), roaming — sometimes surprising distances — in search of prey, then spins a round, silken, egg-shaped cocoon and pupates, usually right on the plant.
Lacewing larvae look so un-beetle-like that gardeners routinely mistake them for pests and squash them. If you find a tiny alligator with prominent jaws crawling through an aphid colony, this looks most like a lacewing larva — but hoverfly larvae and young lady beetle larvae also patrol aphid colonies doing the same good work. Compare the three in the table below before you squish anything, or run our tiny-bugs-under-leaves diagnostic if you are unsure.
The lacewing menu: what each stage eats
Extension sources describe a broad appetite. Compiled from UKY Entfact-708, Cornell's biocontrol factsheet, South Dakota State Extension, and UMN Extension:
| Food | Lacewing larva | Lacewing adult | Notes |
|---|---|---|---|
| Aphids | Yes — the favorite | Sips their honeydew | Larvae can eat hundreds of aphids in a lifetime (UMN) |
| Thrips | Yes | No | Thrips are also hunted by minute pirate bugs |
| Whiteflies | Yes | No | Larvae take eggs and nymphs on leaf undersides |
| Spider mites | Yes | No | Useful where mites and aphids overlap |
| Small caterpillars and insect eggs | Yes | No | Eggs and early instars of soft-bodied caterpillars |
| Mealybugs | Yes | No | Larvae push through the waxy coating |
| Leafhoppers | Yes | No | Nymphs especially |
| Nectar, pollen, honeydew | No | Yes — the main adult diet | Why flowering borders keep adults around |
Lacewing larvae vs lady beetle larvae vs hoverfly larvae
All three are aphid-eating champions. Telling them apart matters — mostly so you do not remove a friend by mistake.
| Lacewing larva ("aphid lion") | Lady beetle larva | Hoverfly larva | |
|---|---|---|---|
| Looks like | Tiny mottled-brown alligator with long curved jaws; no legs obvious at a glance | Dark, spiny, elongated grub, often with orange or red spots; six visible legs | Legless pale-green or brown maggot, tapered at the head end, often half-hidden among aphids |
| Hunts how | Roams and grabs with hollow piercing jaws | Crawls and chews with mandibles | Waves its head end side to side, impaling aphids nearby |
| Favorite prey | Aphids plus thrips, mites, whiteflies, caterpillar eggs — the generalist | Aphids first and foremost — the specialist | Aphids, especially dense colonies |
| Stays or wanders | Wanders widely; pupates on the plant | Stays near the colony; pupates on leaves or stems | Stays put at the colony; pupates nearby |
Verdict — choose lacewing larvae if you want the broadest coverage: they take thrips, spider mites, whiteflies, and caterpillar eggs in addition to aphids, and they are the easiest of the three to support long-term with flower borders. Choose lady beetle larvae if aphids are your single main problem and you want the most famous aphid specialist — see our ladybugs and aphid control guide. Choose hoverfly larvae if you want free help with zero effort: plant flowers, and hoverfly adults will arrive on their own and lay eggs right inside aphid colonies.
Attract them: feed the adults, shelter the young
In IPM, habitat comes before everything else — and for lacewings, habitat means flowers. Because adults feed on nectar and pollen, a garden with small, open blooms from spring through fall gives lacewing adults the food they need to stay, mate, and lay those stalked eggs near your pest colonies.
Plant dill in drifts along bed edges: its flat umbrella blooms are a classic beneficial-insect magnet, and you can start with our dill seeds. Tuck cosmos among your vegetables — their open faces feed lacewing adults for months — from our cosmos seeds. Zinnias are another long-blooming workhorse for the beneficial border; sow them from our zinnia seeds. A sunflower or two at the back of the bed adds late-season pollen when little else is blooming — start with our sunflower seeds. Marigolds fill the front edge and bloom relentlessly; try our marigold seeds.
Beyond flowers, give the young a place to finish growing: leave an undisturbed corner with leaf litter or mulch where pupae can overwinter, and avoid tilling every bed bare in fall. Lacewing larvae even camouflage themselves with debris and the shells of eaten prey to hide from ants (SDSU Extension) — a slightly "messy" garden edge is lacewing habitat, not neglect.
Releasing purchased lacewing larvae
Lacewing eggs and larvae are sold by insect suppliers as a biological control, and releases can make sense as one IPM tool among several. In general terms, here is how they work: scatter the larvae near existing pest colonies in the cool of the evening, when they are least stressed; they go to work immediately because the larvae — not the adults — are the predators. Releases work best when prey is already present, because hungry larvae with nothing to eat simply wander off or eat each other.
Set expectations honestly. This is a one-generation treatment, not a permanent colony: the larvae pupate, the adults emerge and fly away unless your garden offers the nectar, pollen, and habitat described above. Think of purchased larvae as reinforcements for a garden that already welcomes lacewings, not a substitute for the flower borders. And never release right after — or right before — any insecticide application; you would be paying to kill your own helpers. For the full helper lineup, see our beneficial insects garden guide.
What kills them: the broad-spectrum trap
The single biggest threat to lacewings is the broad-spectrum insecticide spray. Extension guidance is blunt on this: broad-spectrum contact insecticides wipe out the larvae, the stalked eggs, and the adults alike — the very allies that were controlling the pests for free. Ants are the other enemy: they farm aphids for honeydew and will attack lacewing larvae defending "their" herd, which is one reason ant management matters in aphid control.
This is where IPM order matters. Habitat and scouting come first, biological reinforcements second, and sprays only as a last resort — and then the least-toxic, most targeted option, applied in the evening when beneficials are less active, aimed only at the outbreak, never as a preventive calendar spray. No spray is guaranteed to solve a pest problem, and every spray sets back the predators that do the work between outbreaks.
The 5-minute lacewing scout
Once a week from spring through fall, spend five minutes checking whether your lacewing workforce has reported for duty:
- Pick five plants where you have seen aphids, thrips, or sticky honeydew.
- On each plant, turn over three or four leaves and look along the veins for the stalked eggs — tiny pale dots on hair-thin threads. A 10x hand lens makes this easy (see our gardening tools guide for what to look for in a good lens).
- Scan aphid colonies for the alligators: mottled brown larvae, up to 1/2 inch, with obvious curved jaws. Finding even two or three per plant means the cavalry is on site.
- At dusk, watch for the adults — delicate green fliers with golden eyes drifting around lights and flowers.
- Jot down what you found. Eggs this week mean hungry larvae next week; larvae this week mean the aphid colony is already being handled — hold off on any spray and let them finish.
A lacewing-friendly planting plan
You do not need a meadow — one border does it. Put sunflowers at the back for height and late-season pollen, run a mid-row of zinnias and cosmos for months of open blooms, edge the front with dill and marigolds for the tiny flowers beneficials love, and fill any gaps with mixed blooms from our flower seeds collection so something is always flowering. Keep one corner a little wild for overwintering pupae. Plant it once, and every summer the lacewings will find it on their own.
Frequently asked questions
Are lacewing larvae dangerous to people, pets, or plants?
No. Their jaws are built for soft-bodied insects far smaller than a fingertip, and they have no interest in people, pets, or plant tissue. Larvae are strict predators; adults feed on nectar, pollen, and honeydew. They are safe around children, dogs, and cats.
Will green lacewings eat my plants?
No — neither stage eats plants. The larvae eat insects and insect eggs, and the adults drink nectar, pollen, and honeydew. If you see leaf damage, something else is responsible; lacewings are the cleanup crew, not the culprit.
I released purchased lacewing larvae and they vanished. What happened?
Most likely they dispersed, which is normal. Larvae wander widely in search of prey, and the adults that emerge from them fly off unless the garden offers nectar flowers and habitat. Releases work best as a supplement — prey present at release, no recent sprays, and flower borders planted so the next generation stays.
How do I tell lacewing eggs from pest eggs?
The stalk is the giveaway: lacewing eggs sit singly at the tip of a hair-like stalk about 1/2 inch long, usually near an aphid colony. Most pest eggs are laid directly on the leaf surface with no stalk. That said, this looks most like lacewing eggs — spider egg clusters can confuse at a distance — so confirm with a hand lens, and when in doubt, leave them be.
Can I use insecticidal soap or other least-toxic sprays if lacewings are around?
Even least-toxic sprays kill lacewing larvae and eggs on direct contact — "least-toxic" does not mean harmless to beneficials. If you must spray, do it as a last resort: target only the outbreak, spray in the evening when lacewings are less active, and avoid hitting visible larvae, stalked eggs, or flowering borders. Then re-scout in a few days to see what survived.
Do lacewings help with indoor houseplants?
Releases are used in greenhouses with good results, but on indoor houseplants they are a poor fit: adults are drawn to lights and windows and leave, and larvae wander off the plant. For houseplants, stick with scouting, wiping, and least-toxic targeted treatments — and save the lacewings for the outdoor garden where they thrive.
Sources
- UC IPM Natural Enemies Gallery: Green Lacewings — University of California Statewide IPM Program
- Entfact-708: Green Lacewing — University of Kentucky Entomology
- Common Green Lacewing Biocontrol Agent Factsheet — Cornell Integrated Pest Management
- Green Lacewings: Beneficial Predators for Both Small and Large-Scale Landscapes — South Dakota State University Extension
- Lacewing — University of Minnesota Extension
- Beneficial Insects in New Hampshire Farms & Gardens — UNH Extension fact sheet
Growing the crops lacewings love to protect? Aphids on tomatoes and peppers are favorite lacewing-larva hunting grounds — browse our tomato seeds and pepper seeds, then plant the flower borders above and let the aphid lions stand guard.
