Green lacewings are delicate insects with transparent, lacy wings and often bright green bodies. Many wonder if these familiar garden inhabitants are harmful. This article addresses that question and highlights their beneficial role.
Are They Harmful?
Green lacewings are not harmful to humans, pets, or plants. While their larvae may occasionally bite, these incidents are rare and harmless.
A larval bite might cause a mild skin irritation or an itch, similar to a mosquito bite, but it is neither poisonous nor painful. The adult lacewings primarily consume nectar, pollen, and honeydew, posing no threat to plants or garden inhabitants. Their mouthparts are not designed for biting human skin, and any perceived bite from an adult is more likely an accidental pinch or a case of mistaken identity with another insect.
Life Stages and Benefits
The life cycle of a green lacewing consists of four stages: egg, larva, pupa, and adult. Females lay eggs on slender, hair-like stalks, often on the underside of leaves. This placement protects eggs from predators, including cannibalism by newly hatched siblings.
The larval stage is particularly beneficial and earns the larvae the nickname “aphid lions” due to their voracious appetite. These alligator-like larvae are active predators that feed on a wide range of soft-bodied garden pests, including aphids, mealybugs, spider mites, whiteflies, thrips, and small caterpillars. They use large, sickle-shaped mandibles to seize prey, inject a paralyzing venom, and then suck out the body fluids. A single larva can consume hundreds of aphids during its two to three-week development period. Upon maturation, the larva spins a silken cocoon to pupate, and the adult lacewing emerges a few days later to continue the cycle.
Encouraging Lacewings in Your Garden
Attracting and supporting green lacewings can significantly contribute to natural pest control in your garden. Planting a variety of nectar and pollen-rich flowers provides a consistent food source for adult lacewings, encouraging them to remain and lay eggs. Effective choices include:
- Dill
- Coriander
- Fennel
- Yarrow
- Cosmos
- Sweet alyssum
- Queen Anne’s Lace
Minimizing the use of broad-spectrum pesticides is also important, as these chemicals can harm beneficial insects like lacewings. Providing shallow water sources and creating sheltered areas, such as leaving some leaf litter or brush, offers suitable habitats for lacewings to lay eggs and overwinter. Allowing a small number of pests to persist can also ensure a food supply for lacewing larvae, further encouraging these beneficial insects to thrive in your garden.