Aphid lion larvae consume approximately 400 aphids a week. They compete with lady bugs, parasitic wasps, minute pirate bugs, hover fly larvae, predator stink bugs, praying mantises, assassin bugs, damsel bugs and other beneficial insects for aphids, often making it unnecessary for gardeners to use chemical sprays.
Aphids are phloem feeders, or plant-sap suckers. They congregate on the growing tips of garden plants or on the underside of the leaves. They are small and round and produce a frass (excrement) called honeydew that collects on the plant leaves, making them sticky.
A garden’s aphid population builds at a very high rate due to asexual reproduction by the females giving birth to already pregnant clones. A female aphid can produce 5 to 12 offspring in one day.
Green lacewing (Chrysoperla or Chrysopa spp.) are one-half to three-fourths of an inch long. They have green bodies, golden eyes, and intricate lace wings that they hold upright over their bodies.
The green lacewing adult will fly from flower to flower eating nectar, pollen, honeydew, and small insects. When an adult female comes across a patch of honeydew and aphids, she will lay her white, oval eggs, which remain connected to the plant by a thin filament.
The green lacewing larvae, or aphid lions, have hooked jaws protruding from their heads, making them look more like miniature alligators than lions. As soon they hatch, they begin eating, injecting enzymes into their prey that digest the internal organs. They then suck out the liquidated body fluids. The larvae will eat spider mites, small caterpillars, thrips, mealy bugs, whitefly, and other soft-bodied invertebrates.
Aphid lions will eat for 1 to 2 weeks before pupating in white, round, silken cocoons on concealed parts of the plant. Adult green lacewings emerge and live for 2 to 3 months. Depending on the genus, the insects overwinter in bark crevices or protected locations either as adults or in the pre-pupae stage. They emerge next spring when flowers appear. Depending on temperature and weather, there can be one to four generations per year.
An infestation of aphids attract beneficial insects and pollinators as well as the birds, bats, and larger insects looking to dine on them, increasing species diversity in the garden.
Many chemicals labeled for garden use can harm beneficial insects and prevent their return. Treat only if you see severe plant decline or suspect aphids or phloem feeders are transmitting disease.
As a first step, use water sprays or biopesticides such as soap or neem oil. An alternative to chemical sprays is to release beneficial insects bought online.
Above all, inspect your garden plants and look for signs of garden pests and the beneficial insects that prey on them.
