Green Lacewings - Key benefits and how to attract them
Updated: Nov 7, 2022
If you're growing crops you know harmful insects can ravage and devastate your crops. For organic producers, or those wishing to minimize their use of pesticides, keeping harmful insects at bay can be an extra challenge. One way many organic producers fight back is using natural processes to keep those insects under control. They do this by partnering with beneficial insects. This natural partnership helps eliminate or dramatically reduce harmful insect populations while also minimally affecting the population of beneficial insects and pollinators in your microenvironment.
Green lacewings are one such beneficial insect that can naturally help reduce a variety of garden pests without the need to deploy pesticides. In this article we'll cover how to identify green lacewings, their benefits to your garden and even how to attract them to your farm.
What are Green Lacewings?
Green lacewings are a common flying insect found in the northern hemisphere. They are an insect predator that's best known for feeding on aphids, but their prey might also be other insects like caterpillars, mites, leaf-hoppers and other soft-bellied insects. Adult Lacewings measure between 1/2 and 3/4 inches (about 1-2 cm) long and have a long slender green body, long antennae and golden eyes. They have 4 prominent wings which are delicate looking, almost transparent, with lace like veins throughout. Lacewings are most active at night and are a joy to observe in their element.
A female green lacewing can lay about 200 tiny eggs. Lacewing eggs have an oblong shape attached to tiny silken stalks that attach to leaf surfaces. The eggs are sometimes found in clusters or sometimes by themselves, and change from light to dark green as they mature. The eggs hatch in about 4 days. These eggs are important to look for, as adult lacewings are actually not the beneficial predator. It is the larvae of green lacewings that are the insatiable predators.
Green lacewing larvae are called the Aphid Lion and are voracious feeders and can consume 200 to 300 aphids in the 1-3 weeks before they become adults. Larvae are described as looking like an alligator with a flattened reptile-like appearance and a tapered tail. They are usually pale with dark spots/markings and have six legs. After the lacewing larval stage the larvae pupate into a loose sphere shaped cocoon attached to plants or bark, emerging 10-14 days later.
As we've described, lacewing bugs are part of a natural and organic insect control. They do a lot of work eliminating destructive pests for you while in their larval stage. Here are some of the common garden pests that green lacewing larvae are known to help with:
While adult lacewing flies are not insect predators, they are beneficial pollinators in your garden that feed on plant pollen, nectar and sticky honeydew. They will also lay more eggs and continue the cycle.
How to attract lacewings to your garden
How do we attract these awesome predators? Here are a few tips. (Let us know if you have others we're missing so we can share them here!)
1. Do not use broad-spectrum pesticides
These chemical pesticides are not selective in the insects that they affect and can devastate populations of beneficial insects. Unfortunately, by reducing the population of these beneficial insects you can actually create more room for harmful garden pests to multiply. If you must use chemical insect practices, try using targeted pesticides that selectively target specific pests and avoid the use of broad-spectrum pesticides.
2. Add plants that attract beneficial insects
Many flowing herbs and plants can be used to both increase the bio-diversity of your vegetable garden and also attract beneficial insects. Some plants that can be planted to help attract lacewings include Angelica, Caraway, Coriander, Cosmos, Dill, Fennel, Fern, Poppy, Mallow, Tansy and Yarrow.
3. Keep some bad garden pests around
While no farmer or gardener wants to leave potentially destructive insects on their crops, that act attracts beneficial insects. While pollen, nectar and sticky honeydew will help attract beneficial bugs like lacewings, a solid source of aphids (or other pests) offer a welcome feast for beneficial insects. This bounty of food will encourage female lacewings to deposit hundreds of eggs that will hatch into an army of pest eaters. It's all a balance.
4. Attract them with sugar spray
By applying a mixture of sugar and water to plants where aphids and other pests are taking up residency you can help to attract beneficial insects like green lacewings. This sugary-sweet mixture will simulate the honeydew-like secretions created when plants are attacked by aphids, mealybugs and other harmful insects. This attracts other insects, like honeybees, lacewings and ants. The simulation will help to attract beneficial insects like lacewings to encourage them to lay their eggs, resulting in an army of lacewing larvae on the hunt of aphids.
5. Buy lacewings
You can buy populations of many beneficial insects like ladybugs and green lacewing bugs. You can often find them for sale online or at a local garden center.
For lacewings you can typically buy them at various stages of the lacewings life cycle:
Eggs: Eggs can be spread around your garden or greenhouses or applied directly to plants that show increased pressures from aphids.
Larvae: Lacewing larvae are an exceptional way to quickly reduce the population of harmful pests. Because the lacewing larvae are such veracious eaters of pests they can make short work of them in a short amount of time.
Adults: Adult lacewings can be bought and may help to establish a local population of lacewings. They are also beneficial, but not prolific, pollinators.
These unassuming insects are one of various beneficial insects that you should try to protect and encourage to take up residence in your garden. These unassuming little green bugs are an excellent ally in the fight against crop destroying insects and when provided with a healthy home they can be a serious weapon in the organic farmer's arsenal.
To learn more, check out some of these other resources:
Ecological Understanding of Insects in Organic Farming Systems