Lacewings

A common theme you will find in many BugInfo articles is that a great many of the insects and other arthropods you may find in and around your home are quite beneficial to us. Their role in nature may be one of recycling of nutrients, decomposing dead trees, pollination of flowers, or feeding on other kinds of insects as either parasites or predators. The difficulty, for most people, is in identifying that insect that is crawling or flying through the house, because there are so many different kinds of bugs out there that it is hard to learn their names, much less to know much about them. We hope that is the value of BugInfo, in deciphering this dizzying array of insects for you.

One of the common insects you are bound to see now and then is called a Lacewing, and there are nearly 90 different species of them in North America, including green and brown forms. These insects undergo "complete" metamorphosis, in the manner that butterflies do, and the adult and larval stages look very different from one another, as do caterpillars and adult butterflies. The adult lacewing is a very delicate insect, with long wings and thin bodies, and without strong flight muscles their flight is a very slow, fluttery flight rather than the rapid flight you might observe with dragonflies. The adult insect is attracted to lights, and commonly they are drawn to your porch lights, where they may be found resting on the walls in the morning. Or, when someone opens the front door at night one or two of these weak fliers may be drawn into the house, where they are now found flying slowly around looking for a way back out. They are completely harmless, and the best action would be to carefully capture the insect in your hands and release it to the outside world, where it can continue its business of producing offspring and eating the insects you don't want on your plants.

Both the adult and the larva of lacewings are predators, feeding on a wide array of small insects that feed on our garden plants. The list includes mealybugs, mites, whiteflies, small moth or beetle larvae, and perhaps most commonly aphids. In fact, their appetite for aphids is so strong that lacewing larvae have earned the nickname of "aphid lion", and to watch one eat an aphid is fascinating. The lacewing larva is equipped with a pair of jaws that look like ice tongs, and when it discovers a cluster of aphids it snatches one off the surface by impaling it with its jaws. Once the aphid is pierced a pumping action by the aphid lion sucks out all those wonderful juices from the inside of the aphid, and the empty carcass is then tossed aside and the next victim chosen. With a pair of mandibles of its own the adult lacewing also has no problem dispatching large numbers of aphids in a short period of time, although the adults will also satisfy their sweet tooth with the occasional meal of nectar or honeydew.

Another name for the larva of the lacewing is "trash bug", an unfortunate nickname that has nothing to do with its food preferences. Like the larvae of some other kinds of insects, such as assassin bugs, the aphid lion of some species may stick pieces of plant material onto its body in an effort to create a camouflage so that it cannot be seen by its own enemies. After all, the food chain dictates that those things that eat other animals are themselves eaten by some organism. Hiding under a covering of inedible debris seems to work well for them as they move about on the surface of a plant. While the aphid lion is, in reality, quite harmless to people, it is not impossible for it to poke at someone's skin with those sharp, pointed mandibles. The result could be a slight "bite" sensation, which I have heard from people who accidentally got one of these critters on them. Since the larvae are on plants it may be possible for one to fall off of some leaves that you brush through, perhaps landing on the back of your neck. In their fear of being harmed they might grab at you, but with no venom and being very small they really cannot harm you.

Another stage of this insect that you may have seen at one time, without realizing what you were looking at, is the eggs. The female Green lacewing often places these in clusters of a couple dozen eggs, each egg sitting at the top of a thin stalk about one half inch long. The female creates this stalk by touching the tip of her abdomen to the surface of the leaf and drawing it up, leaving the threadlike stalk below, and then placing the single egg right at the end. Since she went to all the trouble to do this there must be a good reason for it, and one likely reason would be to place that precious egg well above the leaf surface so that other insects do not eat it, including other aphid lions that might be the first ones to emerge from their eggs. These eggs, whether found singly or in clusters, occasionally will be on house plants, the result of that female entering your home by accident, and needing to deposit her eggs in a timely manner. With any luck you are not going to have pest insects feeding on your houseplants, so the proper course of action might be to sacrifice that leaf with the eggs on it, and deposit it in your garden, perhaps on a rose bush that would provide the food the soon-to-be aphid lions will need.

These are common insects that you are bound to see on a regular basis. The female is capable of depositing several hundred eggs in her lifetime, and may live for several months, supplying that steady stream of biological control of pests in your garden. The brown lacewings, which look very much like the green lacewings, but are light brown instead of that lime green color, may place their eggs directly on the surface of a leaf, rather than creating the long stalk that the green species do. There are nearly 60 species of the brown lacewings, and amazingly all of the species in North America can be found in Florida. You can purchase lacewings from supply houses, and this may be of benefit when you release them in your garden. Since the larvae cannot fly they would continue to do their feeding in the plants you release them to. Insects can be fascinating if we will stop to watch them awhile.