Green Lacewings: How To Use Them For Garden Pest Control

green lacewings n excellent beneficial insect for biological pest control in the garden

Green lacewings are small, delicate insects and members of the group of insects termed as “net-winged.” There are many different species of these dainty green creatures which you’ll find in all temperate and tropical parts of the world.

Lacewings are extremely beneficial insects for biological pest control! In their adult stage they are valuable pollinators, and in their larval stage, these ferocious predators devour all manner of harmful pest insects.

Among beneficial garden fauna, Green Lacewing larvae are some of the most efficient natural predators and great for aphid control. Some types of adult lacewings also eat pest insects, but most adults are not predatory.

The larvae (aka Aphid Lions) are aggressive with a voracious appetite. After hatching, they quickly range far and wide in search of garden pests to consume. Their diet includes:

Aphid lions are eating machines, constantly on the prowl for their next meal. A lacewing larva grows very rapidly and sheds its skin several times between hatching and enveloping itself into a cocoon in preparation for its final metamorphosis into adulthood.

Growing, skin-shedding, spinning a cocoon and metamorphosing are all energy intensive activities, so baby lacewings must eat almost constantly.

As larvae, they consume vast quantities of insect pests and insect eggs. Although the list above includes most of their prey, the fact is they will eat any slow-moving, soft-bodied insect they encounter and any insect eggs.

They will also consume one another if given the opportunity. While this cannibalism is rather dreadful, remember it is part of the natural selection process. The larger, stronger nymphs cull out the smaller, weaker ones and ensure that only the strongest of the lot grow into adulthood and reproduce.

The lacewing larval stage lasts from one to three weeks. Once the larvae metamorphose into adults, they will (for the most part) no longer be predatory. Adult lacewings are tiny, green flying insects with delicate, lacy wings. They consume aphid honeydew, eat nectar and pollen from flowers.

green lacewings - aka aphid lion - feeding

How To Use Green Lacewings In Your Garden

Because the larval stage is short, when you introduce lacewing eggs and/or larvae into your garden, plan to do it in phases. You can purchase lacewing eggs or larvae at your local nursery or from online suppliers. Figure on getting enough to distribute ten eggs to each of your plants. This adds up to about a thousand eggs for every two-hundred square feet of garden space.

Be sure to scatter the eggs or larvae amongst the leaves of your plants. If you put them all together in a clump, you’ll likely lose some to cannibalism. Keep your eyes peeled for the emerging larvae. Know what to look for, so you don’t accidentally kill off your insect helpers.

Hatchling aphid lions are very tiny and a dull grayish-brown in color. They have long, slightly plump bodies which some people say looks like a tiny alligator. They come equipped with a set of long, sharp pincers in the front, which they use to capture, immobilize and consume their prey.

The aphid lion impales an aphid or other soft-bodied insects between its two sharp pincers. It then injects digestive enzymes through the pincers. Finally, it sucks the contents and body fluid of its hapless victim’s body out using the sharp pincers as straws. The whole process is quite a dramatic process, and you can see it carried out here:

Video: Green Lacewing Larvae vs. Bird Cherry-Oat Aphid

Buying & Using Green Lacewing Eggs

Both local and online nursery suppliers sell lacewing eggs or larvae like these. The shipped eggs are mixed into bran or rice hulls with moth eggs mixed in to provide food for the larvae should they hatch in transit.

These tiny moth eggs also provide food in the form of the eggs or moth caterpillars after you have distributed the eggs in your garden. You needn’t worry about caterpillar infestation. The aphid lions will attend to that problem for you before it begins.

Distribute the eggs as soon as possible after receiving them; however, don’t distribute them when it is very hot or very cold. If you receive your shipment or bring your package of eggs home from your local nursery on a hot day, place the package in your refrigerator for up to 48 hours.

If you receive lacewing eggs during the heat of the day, wait until the cool of the early evening or morning to distribute them. Naturally, you should wait until all danger of frost has passed to pursue this project. Lacewing eggs and larvae need the dependable warm weather to hatch quickly and thrive.

It’s best to plan two or more releases timed a week to ten days apart. By distributing lacewing eggs or releasing aphid lions in waves, you can be certain of having good predatory insect coverage throughout the growing season.

Video: Releasing Green Lacewings in the Vegetable Garden

Lacewings In Nature

Green lacewings are natural to a wide variety of environments. You find them in significant numbers in agricultural settings, home gardens, and yards. The adults are pretty and dainty with soft, lime green bodies, translucent wings, and large, orb-like golden eyes. As adults, they may cluster around porch lights and other light sources in the evening.

In a natural setting, female lacewings lay minuscule, oblong, pale green eggs suspended by silken stalks on the undersides of leaves. The stalks serve the purpose of protecting the eggs from predators and preventing the hatchlings from consuming one another.

If you come across a cluster of lacewing eggs, you can tell if it is a fresh clutch or one almost ready to hatch by observing its color. Freshly laid eggs are green. As they get closer to hatching, they become darker and brown just before they hatch.

Only four days elapse from the time the eggs are laid until they hatch. Larvae quickly look for food and grow very rapidly. They shed their skin, grow and develop three times before spinning their cocoon for the complete metamorphosis.

When the larvae complete their initial instars (growth and shedding cycles), it spins a small, loose cocoon which completes its final transformation. You may have seen these cocoons under the loose bark of trees or attached to plant stems. This pupal stage lasts for five days

When the larvae have metamorphosed and are ready to emerge from the cocoon, it cuts a neat little trap door out of one end and squeezes its way into the world. It is very vulnerable at this point and must perform some difficult tasks before it is ready to fly.

Before it can spread its wings and fly, it must shed a protective film that encloses its entire body and wings. This process takes up a lot of energy. Once the film drops, the tiny, dainty green insect must air its wings until they spread and dry. Then it can fly about seeking pollen, nectar, and honeydew to eat.

Without abundant sources of these foods at hand, it must quickly fly to find the resources needed to survive, mate and lay eggs. If the weather is favorable and predators like birds do not eat the little creature, adult lacewings can live up to six weeks.

In areas with mild winters, every stage of lacewing can over-winter with some protection from the elements. In colder climates, eggs may survive in very sheltered settings. Larva in the pupal stage may also overwinter inside the cocoon. When this is the case, the pupa becomes completely dormant, and emergence from the cocoon delays until the weather warms up.

Video: How To Release Green Lacewing Eggs

Crysopa life cycle (#308)

Encouraging & Maintaining Your Lacewing Population

If you have not been spraying poisons and pesticides in your yard, you probably already have some lacewings in residence. You can increase these numbers by allowing a small and separate section of your garden to go fallow and provide a home for aphids and other pests desired by lacewing larvae. Because adult lacewings eat the aphid honeydew, allowing a controlled aphid infestation will attract them to your garden.

Just a few plants with an abundance of aphids producing honeydew will soon attract adult lacewings wishing to lay eggs and even aphid lions looking for a meal. These tiny larvae can travel as far as 150 feet in search of food. This distance is a phenomenal considering their diminutive size.

Promoting Beneficial Insects In The Garden: Ladybugs, Parasitic Wasps, and Green Lacewings

Lacewing Larvae Have A Strong Impact On Pests

Because they are aggressive, voracious and not the least bit picky, aphid lions can make a huge difference in the number of insect pests in your yard or garden. It is why organic commercial agricultural settings deploy them.

Professional growers of eggplant, tomatoes, peppers, peaches and more make proper use of these tough little predators to tackle aphids. They have also been successfully used in commercial agricultural settings to control:

  • Colorado Potato Beetles
  • European Red Mite
  • Tobacco Budworm
  • Corn Earworm
  • Mealybugs
  • Green Peach Aphid

Using Lacewings In Your Greenhouse

In the microcosm of a greenhouse setting, you will get the best results with a very focused release schedule of larvae. To address an immediate infestation problem, release larvae in waves at a predator/prey ratio of one-to-three or one-to-five.

There are no hard and fast rules as to how many waves of larvae you should release or how frequently you should release them. You must use your judgment based on the severity and type of infestation. Once established, Lacewings can survive and thrive indefinitely in the controlled, safe setting of a greenhouse.

Video: Rearing Green Lacewings: Chrysoperla johnsoni

Ensuring The Success Of Your Lacewings

Naturally, since aphid lions are living creatures, their effectiveness and efficiency can be affected by many factors. Take every step necessary to ensure their success.

  1. Acquire the right number of eggs or larvae at the right time of year.
  2. Distribute or release your eggs or larvae on a comfortably warm, still day.
  3. Be sure that the pests you are dealing with are subject to aphid lion predation.
  4. Distribute or release waves of eggs and/or larvae for good coverage throughout the growing season.
  5. Don’t rely solely on friendly fauna to keep your yard and garden pests under control. Overall smart yard and garden care habits go far to help you grow strong, healthy plants that possess natural resistance to pests and disease.

Green lacewings and their larvae can be an important and useful component of your insect pest management plan in your yard, garden and greenhouse. Used in conjunction with manual control, natural deterrents, and organic treatments, they can be great allies helping you attain and maintain a healthy growing environment.

Buy Green Lacewings Online Here

Sources: buglogical.comentomology.wisc.edu

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