FEBRUARY
2003

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

2-13-03

Download the audio of On Six Legs: MP3, WMV.

Some Insects Have A Lot of Nerve


The name of the insect order Neuroptera is derived from the Greek word neur, which means nerve. Combined with pter, Greek for wing, the order name literally means nerve wing. It is a good name because the wings of Neuroptera are clear with numerous veins resembling a bunch of branched nerves.

Insects of the order Neuroptera are not among the most common insects. However, one group, the lacewings, are frequently found in our gardens. Lacewings are considered beneficial by gardeners because they are predators on pest-like aphids. 

Some people think lacewings look like miniature prehistoric monsters. Scientists generally agree that insects are an ancient life form and, compared to humans, are prehistoric. However, the order Neuroptera is generally not considered to be among the oldest types of insects. They just look that way.

Lacewings are monsters when it comes to eating habits. Like most species of Neuroptera, both adults and immatures feed on other animals, mostly insects. The adults have regular chewing mouthparts, and the immatures have sickle-like jaws that are used to suck the juices from prey. These larvae are sometimes called aphid lions in reference to their ferocious eating habits. Aphid lions have even been known to clamp down on a human now and then.

So vicious are immature lacewings as predators, if given the chance, they will consume lacewing eggs before they hatch. Lacewing mothers prevent this from happening by attaching eggs to stalks, which keep the eggs out of reach of newly hatched monsters.

Lacewings have been called golden-eyed lacewing flies. Of course, they are not scientifically flies, even though they do fly. However, their eyes do have a metallic, golden color reflection in some lights. They also have been called stink flies. This is based on the fact that they produce a disagreeable odor when handled.

Another group of Neuroptera are called antlions. The antlions get their name from the food of immatures, which is frequently ants. Immature antlions dig pits to capture their food. The pits are located in sandy soil and are produced by the immature placing grains of sand on its head and then tossing the grains out of the pit. When completed, the pit is conical in shape with the antlion residing in a hole at the base. 

Unfortunate insects that tumble into the pit of an antlion are consumed by the hungry occupant. Once the juices of the victim are consumed, the carcass is tossed from the pit like a rag doll being thrown from the crib by a young child.

There are several species of antlions in the United States. They vary considerably in size with some having a wing expanse of four inches. The adults have short, clubbed antennae and four similar wings. In general shape, they appear much like a damselfy. The eminent entomologist L. O. Howard wasn't impressed with their looks; in the "The Insect Book," he wrote that the adult antlions "are not especially attractive in their personal appearance."

Maybe the same should apply to other adult members of the Neuroptera. One group is called a snakefly, since it has an elongated prothorax and head with large eyes, much like a snake. There is also one called a mantipsid; it resembles a praying mantid with large grasping forelegs.

Probably the most fearsome looking of the Neuroptera are the dobsonflies, which are also called fishflies. With a wing spread of up to five inches, a fluttering flight and an attraction to light, this insect sometimes attracts a great deal of attention when it shows up near a porch light. This is especially true for the males, which have greatly enlarged mandibles protruding from the front of the head. 

Immature dobsonflies are aquatic creatures called hellgrammites and are a favorite food of predatory fish like bass. Hellgrammites are also prized by fishermen as bait. But hellgrammites are not a docile-looking insect. Appropriate to the order name for this insect, it takes some nerve to put one on the hook!

 

 

Writer: Tom Turpin
Editor: Olivia Maddox