Lacewings are among the most valuable beneficial insects in gardens and agricultural systems, with their voracious larvae earning the nickname “aphid lions” for their remarkable predatory capabilities consuming hundreds of pest insects during development. These delicate-appearing insects are increasingly recognized by gardeners and farmers as essential natural pest control agents that reduce or eliminate the need for chemical pesticides when their populations are encouraged and protected.
Their presence indicates healthy ecosystems with balanced predator-prey relationships, making lacewings welcome garden inhabitants despite occasional accidental indoor appearances when attracted to lights during evening hours.
What are lacewings?
Lacewings are predatory insects belonging to the order Neuroptera, with green lacewings (family Chrysopidae) and brown lacewings (family Hemerobiidae) being the most common and beneficial groups. These delicate insects are named for their intricately veined, translucent wings resembling fine lace.
Both adults and larvae of most species are predators, though adult green lacewings primarily feed on honeydew, nectar, and pollen while their larvae are voracious predators. Lacewings occur worldwide in gardens, agricultural fields, and natural habitats where they provide valuable biological control of aphids, mites, thrips, whiteflies, and other soft-bodied pest insects.
What do lacewings look like?
Adult green lacewings are delicate insects measuring 1/2 to 3/4 inch in length with slender pale green bodies, large golden or copper-colored eyes, and four translucent wings with intricate network-like venation giving them their common name. Their wings are held roof-like over their bodies when at rest. Brown lacewings are smaller (1/4 to 1/2 inch), darker brown, and less commonly noticed.
Lacewing larvae are elongated, alligator-like predators measuring up to 1/2 inch with prominent sickle-shaped mandibles, brown or gray mottled bodies, and often carry debris on their backs for camouflage against prey and predators.
Lifecycle of a lacewing
Lacewings undergo complete metamorphosis with egg, larval, pupal, and adult stages adapted to their predatory lifestyle. Females lay distinctive oval eggs individually on the ends of silk stalks attached to leaves, creating characteristic “fairy lights” appearance protecting eggs from cannibalism and predators. Each female produces 100-300 eggs during her 4-6 week adult lifespan. Eggs hatch within 3-6 days depending on temperature.
Larvae are voracious predators passing through three instars over 2-3 weeks, consuming hundreds of aphids and other prey. They have hollow, sickle-shaped mandibles that pierce prey and suck out body contents. When fully grown, larvae spin silken cocoons on leaf undersides or protected locations and pupate for 1-2 weeks. Adults emerge, mate within days, and begin egg-laying, completing development in 4-6 weeks under favorable conditions. Multiple generations occur annually, with 2-4 generations typical in temperate regions.
Are lacewings dangerous?
Lacewings are not considered dangerous and are entirely beneficial insects posing no threats to humans, pets, plants, or property. Adults are fragile, harmless creatures that don’t bite aggressively, sting, or transmit diseases. Larvae, while fierce predators of pest insects, don’t attack anything larger than small arthropods.
They don’t damage plants, structures, or belongings. Lacewings are highly beneficial predators consuming pest insects in gardens that would otherwise damage gardens and crops. Their occasional appearance indoors when attracted to lights represents harmless incidents easily resolved by turning off lights and gently releasing lacewings outdoors where they continue providing valuable pest control services.
Can lacewings bite humans?
Adult lacewings rarely bite humans, but may deliver mild, exploratory bites when handled or trapped against skin, causing brief pinching sensations and minor localized redness lasting minutes to hours without medical significance. These “bites” are defensive reactions rather than aggressive behavior or feeding attempts, as lacewings don’t feed on blood and can’t effectively pierce human skin.
Lacewing larvae theoretically could bite if handled but rarely do and their tiny mandibles adapted for piercing soft-bodied insects cause minimal sensation. Any discomfort from lacewing encounters is trivial compared to mosquito or fly bites and doesn’t warrant concern or control measures against these beneficial insects.
Do lacewings eat other pests?
Yes, lacewings are exceptional generalist predators consuming numerous garden and agricultural pest species. Lacewing larvae are particularly voracious, earning the nickname “aphid lions” for consuming 200-300 aphids during their 2-3 week larval development, though they also prey on spider mites, thrips, whiteflies, small caterpillars, mealybugs, scale insects, insect eggs, and other soft-bodied arthropods. Larvae actively hunt prey on plant surfaces, using their hollow mandibles to pierce victims and suck out body contents.
Adult green lacewings primarily feed on honeydew, nectar, and pollen, providing limited predation, while adult brown lacewings remain predatory. The combination of multiple prey species consumed and multiple generations annually makes lacewings among the most valuable biological control agents in integrated pest management programs.
Commercial suppliers sell lacewing eggs and larvae for augmentative releases in gardens and greenhouses, where they establish populations providing ongoing natural pest suppression reducing or eliminating pesticide needs.
Do most gardens have lacewings?
Most gardens have at least some lacewing activity, though populations vary based on prey availability, pesticide use, and habitat quality. Gardens with diverse plantings, abundant flowering plants providing nectar and pollen, and minimal pesticide applications typically support higher lacewing populations.
Well-established gardens with balanced ecosystems often have resident lacewing populations that increase when pest outbreaks provide abundant food for larvae. However, intensive pesticide use kills lacewings along with target pests, requiring recolonization from surrounding areas. Urban gardens may have lower lacewing populations than rural settings due to limited natural habitat nearby.
Encouraging lacewings through appropriate plantings and conservation practices increases their presence and effectiveness.
What attracts lacewings?
Lacewings are attracted to gardens providing both prey for larvae and food sources for adults. Flowering plants producing nectar and pollen including angelica, coriander, dill, fennel, yarrow, tansy, and various composite flowers (asters, sunflowers) attract adult green lacewings seeking carbohydrate sources.
Aphid populations and other soft-bodied pest concentrations attract egg-laying females seeking food sources for their predatory larvae. Gardens with diverse plantings, some wilder areas with native plants, and minimal pesticide use create favorable habitats. Lacewings are also strongly attracted to lights at night, sometimes entering homes through open windows near illuminated areas during their nocturnal activity periods.
How to know if you have a lacewing infestation
Lacewing “infestations” don’t occur since these beneficial insects don’t cause problems, though recognizing their presence helps appreciate their pest control contributions:
- Distinctive stalked eggs on leaves: You might notice tiny oval eggs attached to leaves by thin silk stalks resembling lollipops or “fairy lights,” indicating female lacewings are laying eggs.
- Alligator-like larvae on plants: It’s common to discover elongated brown or gray larvae with prominent curved mandibles actively hunting on plant surfaces where pest populations exist.
- Adults attracted to lights: You are also likely to see delicate green insects with large golden eyes and lacy wings congregating near outdoor lights or occasionally flying indoors through windows.
- Reduced pest populations: You might experience declining aphid, mite, or other pest problems as lacewing larvae consume substantial numbers during their development.
- Silken cocoons on leaves: You might also find small white or tan silken cocoons attached to leaf undersides where lacewing larvae have pupated before adult emergence.
How to prevent a lacewing infestation
Preventing lacewings is counterproductive since they’re highly beneficial predators, though these practices limit their presence if genuinely unwanted:
- Use broad-spectrum pesticides regularly: Apply chemical insecticides that kill beneficial insects along with pests, eliminating lacewing populations though this increases pest problems requiring more treatments.
- Remove flowering plants: Eliminate nectar and pollen sources that attract and sustain adult lacewings, though this also harms pollinators and reduces garden biodiversity.
- Reduce outdoor lighting at night: Minimize exterior lights that attract flying lacewings during evening hours, preventing their congregation near buildings and subsequent indoor wandering.
- Create sterile landscapes: Maintain manicured lawns without diverse plantings that support beneficial insect populations, though this eliminates natural pest control and ecosystem services.
- Consider welcoming them instead: Recognize lacewings as valuable garden allies providing free, sustainable pest control worth encouraging rather than preventing through conservation biological control practices.
When to call a professional
When dealing with garden pest populations including aphids, mites, thrips, or other soft-bodied insects damaging your plants and home garden, professional pest control services can provide effective integrated pest management solutions that incorporate beneficial insects like lacewings alongside targeted treatments. At Aptive, our pest control experts understand the importance of preserving beneficial predatory insects including lacewings.
If you’re experiencing persistent garden pest problems despite the presence of beneficial insects, need help identifying whether insects in your garden are harmful pests or helpful predators like lacewings, or want guidance on establishing integrated pest management programs that work with nature rather than against it, don’t wait—contact Aptive today for a free quote.
FAQs about lacewings
Here are some commonly-asked questions about lacewings from homeowners.
Q: What part do lacewings play in ecosystems?
Lacewings are crucial natural predators maintaining balanced insect populations in ecosystems by controlling aphids, mites, and other herbivorous insects that could otherwise reach outbreak levels damaging plants. They function as biological control agents in food webs, converting pest insect biomass into food for birds, spiders, and other predators that consume lacewings.
Their predation reduces plant damage, supporting vegetation health and productivity throughout ecosystems. Adult lacewings also serve as pollinators when visiting flowers for nectar and pollen. By regulating pest populations naturally, lacewings reduce the need for pesticide applications that harm non-target species, supporting overall ecosystem health and biodiversity in agricultural and natural habitats.
Q: What host plants are common for lacewings?
Lacewings don’t require “host plants” like plant-feeding insects, but certain flowering plants attract and sustain adult populations. Common beneficial plantings include members of the carrot family (Apiaceae) such as dill, fennel, coriander, angelica, and Queen Anne’s lace providing accessible nectar and pollen. Composite flowers including yarrow, cosmos, sunflowers, and asters attract lacewings.
Alyssum, tansy, and various herbs support adult feeding. These plants should be allowed to flower rather than harvested before blooming. Diverse plantings with continuous flowering throughout the season maintain lacewing populations. Integrating these “insectary plants” throughout gardens and field margins provides nutrition supporting lacewing reproduction and longevity.
Q: How long do lacewings live?
Adult green lacewings typically live 4-6 weeks under favorable conditions, though lifespan varies with temperature, food availability, and species. The complete lifecycle from egg to adult death spans 4-8 weeks depending on environmental conditions, with warmer temperatures accelerating development. Multiple generations occur annually, with 2-4 generations typical in temperate climates and continuous reproduction in warm regions.
The larval stage lasts 2-3 weeks, pupal stage 1-2 weeks, and egg stage 3-6 days. Some adult lacewings may overwinter in protected locations, surviving several months in dormancy before becoming active in spring. Their relatively short individual lifespans are offset by multiple overlapping generations maintaining populations throughout growing seasons.
Q: Do lacewings eat spider mites?
Yes, lacewing larvae are effective predators of spider mites, consuming both eggs and motile stages during their 2-3 week development. A single lacewing larva can consume hundreds of spider mites along with other prey. While lacewings prefer larger prey like aphids when available, they readily feed on spider mites, particularly during early larval instars when their smaller size makes mites appropriately sized prey.
Lacewings are often commercially released in greenhouses specifically for spider mite control. However, specialized predatory mites (Phytoseiidae) are generally more effective spider mite control agents due to their exclusive focus on mites. Lacewings work best as part of integrated pest management combining multiple natural enemies.
Q: Are lacewings or lady bugs better for gardens?
Both lacewings and ladybugs (lady beetles) are excellent beneficial insects with complementary roles in gardens. Ladybugs are more visible, easier to recognize, and both adults and larvae are voracious aphid predators. However, commercially purchased ladybugs often disperse from release sites seeking better habitat.
Lacewing larvae may consume more total prey (200-300+ aphids) than individual ladybug larvae, and lacewings prey on broader pest ranges including mites and thrips. Lacewings are more likely to establish resident populations when appropriate flowering plants are present. The best approach involves encouraging both through diverse plantings, habitat conservation, and minimal pesticide use, allowing natural predator communities with multiple species providing lasting, resilient pest control.
