Green lacewing (scientifically known as Chrysoperla rufilabris) is widely used in various situations to control many different pests. Many species of adult lacewings do not kill pest insects, they actually subsist on foods such as nectar, pollen and honeydew. It’s their predacious offspring that get the job done. If you’re looking for effective aphid control, green lacewing larva should help do the trick.
The adult lacewing lays her eggs on foliage where each egg is attached to the top of a hair-like filament. After a few days the eggs hatch and a tiny predatory larva emerges ready to eat some aphid pests.
Lacewing larvae are tiny when emerging from the egg, but grow to 3/8 of an inch long. They’re known as aphid lions since they voraciously attack aphids by seizing them with large, sucking jaws and inject a paralyzing venom. The hollow jaws then draw out the body fluids of the pest, killing it. Of all available commercial predators, this lacewing is the most voracious and has the greatest versatility for aphid control in field crops, orchards, and greenhouses.
Each green lacewing larva will devour 200 or more pests or pest eggs a week during their two to three week developmental period. After this stage, the larvae pupate by spinning a cocoon with silken thread. Approximately five days later adult lacewings emerge to mate and repeat the life cycle. Depending on climatic conditions, the adult will live about four to six weeks.
Each adult female may deposit more than 200 eggs. For best results, habitats should encourage the adults to remain and reproduce in the release area. Nectar, pollen, and honeydew stimulate their reproductive process. If these food sources are not available, adults may disperse. An artificial diet called Wheast is available to provide the adults with the necessary nutrition they need for reproduction. Wheast powder mixed with sugar and water is used at Beneficial Insectary to help mass-rear the lacewing. Studies by universities and the USDA have shown that spraying field crops with a Wheast/sugar/water mixture increases egg laying considerably. Green lacewing adults can survive the winter in protected places but have a difficult time surviving cold winters.
Green Lacewing are available in the following life stages:
To minimize egg mortality, humidity should be approximately 75%. Warmer temperatures will speed up larval emergence, but the eggs should not be held at more than 80°F. For small areas, sprinkle the contents of the container(s) over the entire target area. For large areas you may need to mix eggs with additional inert ingredients such as vermiculite, bran, saw dust, etc. to help dispersal. You may also release eggs on every other row on alternating dates. If eggs are purchased on perforated hanging cards, hang the cards, from the hole in the card, near the underside of leaves in the target area.
Adults: Green Lacewing adults are sold in containers of 100, 250 or 1,000 and should be released the day received. If immediate release is not possible, moisten the accompanying sponge in water and replace it. We do not advise refrigerating the adults. One adult female lacewing can deposit up to 800 eggs in its four- to six-week lifespan. Proper habitat and food will encourage adults to stay in the area, continuing the Better Pest Management lifecycle. To release, remove the top screen and use a piece of cardboard to regulate the amounts released throughout the target area.
Larvae: Lacewing larvae are sold in bottles of 1,000 or 6×8 inch hexcel rearing frames containing at least 400 larvae. Both containers have a limited supply of food, so the larvae must be used as soon as possible. Lacewing larvae are safe to humans and animals, but vigorously attack their prey. They are ideal for aphid control as each lacewing larva can devour 200 or more pests or pest eggs during the two- to three-week larval stage.