Snakeflies In The Garden
You will find many kinds of odd insects in your garden or in your home, and very often they will be beneficial insects of some kind. If we do not know what kind of “bug” it is we are liable to take the better-safe-than-sorry route and kill it. Hopefully, on BugInfo, we can continue to present you with information on all of the beneficial insects as well as the problem kinds, and allow you to make good choices when it comes to deciding whether that bug can live or must die.Snakeflies are one of those odd little characters. They are highly beneficial as predators that feed on many other kinds of insects. The adult insects feed on a variety of your most hated plant pests, such as aphids, psyllids, scales, and other small, soft insects that suck the plant fluids from ornamentals and orchard plants. The larva of the snakefly can be a very aggressive predator, but harmless to people. It also feeds on any small insects it encounters, such as aphids on the leaves, on small caterpillars, on eggs of other insects, and even on small wood eating insects it can find under loose bark of trees. Apple orchards in the western United States benefit from one species of snakefly, as it is an important predator of the Codling Moth, that moth responsible for the “worm in the apple”. It is the larva of the snakefly that normally lives through the winter months, and this occasionally allows for chance encounters with humans that may worry you if you do not recognize what this insect really is, and the benefit it brings us.
Snakeflies are in the insect Order Raphidioptera, with two families in the order – Raphidiidae and Inocelliidae. Most of our common snakeflies in North America are in the family Raphidiidae. Worldwide there are over 200 different species, with about 25 kinds in the United States, and all of these are found in the western states. The adult insect is about ¾ inch long, with an elongated “neck” area that may be the cause of its common name of “snake” fly. It also has wings that it holds folded over the top of its abdomen while at rest, and it is not a strong flier, having more of a fluttering flight similar to lacewings. The female snakefly is equipped with a very long egg laying device called the ovipositor, and this sticks out the back almost a third of the length of her body. Unknowing people may perceive this as a “stinger”, but the snakefly is incapable of biting or stinging, and is totally harmless to people and pets. It can be handled carefully without harm to either the insect or the person holding it. The female uses this ovipositor to insert her eggs into crevices in the bark of trees and shrubs or old logs. The eggs hatch into active larvae that then set out in search of other insects to dine on.
That chance encounter with snakeflies often occurs in the home, and on occasion in the fall or winter it will be the full grown larva that someone finds. Because the larva is the stage that over-winters, it may happen that it is forced out of its normal hiding place and wanders around in search of a new place to hide in to survive the cold weather. Now and then they find their way into the house, perhaps finding a gap under an outside door, being carried in with firewood, or by some other form of transportation. The larva looks very much like the adult insect but without wings. It has that elongated thorax forming an extended “neck”, and can be around ¾ inch in length. It is a long-legged and very fast moving insect, and when disturbed or threatened in any way it has the curious habit of suddenly running backwards. The intent of this is only to save its life, but we may perceive this as an aggressive movement and a cause for concern. But, like the adult insect, the larvae is harmless, and the best thing you can do if you find one in your home is to carefully place it in your hand or a small container, and place it back outside. Killing it is really doing a disservice to your garden, as you are eliminating an insect that helps protect your plants.
Snakeflies are living fossils, with many extinct kinds found in fossils going back nearly 200 million years. They are one more of the many kinds of interesting and helpful insects in our landscapes, and we should encourage them to be there. Learning to identify and understand the lives of creatures in our gardens is the best way to have a healthy landscape.
