Mosquito Invasion?

If you have walked around the Nature Preserve recently, you probably noticed large numbers of insects rising up from the grass. They have long legs, and bear a strong resemblance to mosquitoes, but they are NOT mosquitoes, thank goodness. These are crane flies, and they do not bite humans at all. Sometimes, crane flies are referred to as “skeeter eaters.” This is an interesting name, but crane flies are not predators and do not eat mosquitoes (not as adults, anyway: some larval crane flies are predatory, and may occasionally eat mosquito larvae). People sometimes refer to crane flies as “male mosquitoes.” This may have come from the knowledge that male mosquitoes don’t bite. Crane flies are not male mosquitoes, although mosquitoes and crane flies are fairly closely related.

Crane flies are considered to be “true” flies, because (unlike other insects) they have only one pair of wings. Other insects like mayflies, dobsonflies, and dragonflies have two pairs of wings. If you look very closely at an ordinary housefly, you will see two tiny, white knobs just behind its wings. These are all that remains of its original second pair of wings. It uses the knobs, called halters, for balance while flying. Look at this closeup for a small protrusion beneath this crane fly’s right wing – that’s its halter. There are dozens of crane fly species in Kentucky, and most are similar in appearance and biology. The most commonly encountered species are in the Tipula genus, and these are typically 3/4″ – 1″ long and gray or brown in color. The University of KentuckyEntomology department has detailed information about crane flies and all other insects found in Kentucky.

Like all flies, crane flies undergo complete metamorphosis with egg, larval, pupal, and adult stages. The larvae are legless and wormlike, and some are very large. Winged adults are active during warm months, especially fall and spring, with different species of adults active at different times during the year. Adults live only for a few days; just long enough to mate and lay eggs. Most species overwinter as larvae or pupae in moist soil, decaying vegetation, or underwater. You may see them flying around tail-to-tail as they mate. Just try not to inhale them as you walk around!