Interview with a Pest Insect Vampire

The bug you wouldn't want to meet in a dark alley ... if you were an aphid.

by the Garden Goddess

ello fellow Earthlings, and welcome to the garden battlefield a place where do-gooders like the green lacewing (Chrysoperla carnea) are doing battle with the forces of gardening evil (pest insects) on your behalf. If any predatory insect deserved the pest control Medal of Diligence, it is the Green Lacewing. Today we will be discussing this voracious gardener's assistant and learn how to ensure that green lacewings are working in your garden. So let's take a walk down to the battlefield ... I mean garden.

The green lacewing is the star of this Goddess' pest control program. Green lacewings are classified as beneficial generalists. This means that these hungry little bugs eat more than one kind of pest insect, and as we will see, they eat a lot of them. The adult green lacewing is a delicate, graceful insect that produces a larvae that is straight out of science fiction, called the "Aphid Lion".

The larval green lacewing or Aphid Lion is a brownish, alligator-looking critter about 1/8 to 1/4 inch long. It is very active and mobile on plants and will vigorously search out prey. Although they are particularly fond of the taste of aphids, lacewing larvae are not specifically aphid eaters. In fact, at mealtime, they are decidedly nonspecific. They enjoy the taste of many pest insects, including mealybugs, spider mites, leafhopper nymphs, caterpillar eggs, soft scales, thrips and some types of whitefly. A single lacewing larvae can consume as many as 1,200 of these pests before pupation and adulthood. Now that's what I call hungry.

Not only are lacewing larvae voracious eaters, they are really creatures after Anne Rice's heart (she's on the Goddess Net). The lacewing larvae actually seize their prey in pincerlike jaws and, once they have subdued their victim, they suck out their juices. Brutality is not an issue in the garden when it comes to biological pest controls. If lacewing populations get too high and competition for food becomes too great, they will eat each other. Built in population control, very cool.

The life cycle of the green lacewing is an interesting few weeks. A green lacewing adult is between 1/2 and 3/4 inches long and has a bright green slender body with transparent pale green wings. They have bright metallic gold eyes and are known in eastern gardens as "golden eyes" (No James Bond comments, please).

Lacewings also have a characteristic "fluttering" flight that is very graceful and allows them to be easily identified. Adults are not predaceous themselves, instead feeding on pollen and nectar from small flowering plants rich in these foods. They also feed on insect honeydew (the civilized name for sucking insect poop) which stimulates the egg laying mechanism due to recognition of prey in the area.

The adult lays tiny green eggs on thin stalks that resemble cattails. The eggs are attached to the underside of leaves, on the bark of trees, or sometimes right in the middle of a bunch of prey insects that are feeding on the plant. In 3 to 12 days, depending primarily on outside temperatures, the eggs hatch and aphid lions are loosed to pillage the countryside.

The larvae immediately begin to actively search for prey. The brown aphid lions then proceed to eat and eat for approximately three weeks before pupating and becoming adults.

Once the larvae is mature, it will spin a small cocoon of a thread that resembles silk. In 5 to 7 days an adult Lacewing emerges from the cocoon to start the cycle all over again.

The life cycle of the Green Lacewing is greatly influence by temperature and climate. In cold weather they have difficulty, and the length of time for a generation to lay eggs will be much longer than it would be in warmer climates. In summer and spring conditions a generation may only take 30 days to complete a cycle. That is why right now is one of the best times to begin releasing green lacewings into your garden.

To keep adult lacewings in your garden, it is helpful to plant lots of nectar-rich flowers. Lacewings love sweet alyssum, dill, and most members of the mint family. Most of these plants are also useful to you, so planting them shouldn't be a problem. Once green lacewings have colonized your garden, you will have fewer pest problems that you have ever experienced. All it takes is a little patience.

When pest insects show up in the garden, avoid the temptation to break out some toxic substance just wait a few days. Lacewings will find the bad guys and the screams will be heard miles away.

Releasing green lacewings into your garden is simple and very cost effective. Many companies "direct ship" to your home, insuring that you get the freshest killers available. Talk to the gardening professionals at Grangetto's Farm and Garden Supply in Encinitas, Escondido, Fallbrook and Valley Center for information on availability. Avoid live bugs in a store you don't know how long that they have been in the store and they could be stressed. This is also a great way to get your children involved in environmentally responsible insect control. They'll be fascinated.

Next time we will find out about Trichogramma parasitoid wasps and a very effective bacteria for caterpillar and worm controls in the garden. Come up and see me sometime!

  Got Questions? Call the toll-free Gardener's help line at (888) 514-4004 or e-mail the goddess with your questions at The Garden Goddess is a trademark of The Organic Gardener's Resource and Design Centre of Encinitas, 293 Neptune Ave. Encinitas, CA. 92024. D.W. Trotter is a consulting horticulturist and an award winning garden designer.