The blood-suckers

I'm pretty sure many of you good people reading this column are not strangers to a horse-fly sucking the blood out of your precious body. Now and then, however, I get calls from strangers to this natural phenomena, so I thought I'd share a few comments about the blood-thirsty creatures.

They are "true flies," in the order Diptera (which means two-winged insect - all the other orders have four wings). It's the females of all the bloodsucking flies who delight in feasting on the blood from our bodies; the males are-literally-flower children.

Whether mosquito, gnat, black fly, horsefly or deerfly, it is the female who must feed on the blood of mammals in order to have the protein necessary to manufacture healthy, viable eggs.

In nature, survival of the species is the commandment everything must follow-be it plant or animal. It's in the genes; nothing else matters, only survival.

Most of the large, bloodsucking flies are found in the zoological family Tabnanidae. While horsefly or deerfly are terms describing the big, blood-sucking flies, the miserable beasts have a list of other names as well: breeze flies; bulldog flies; what-in-the-h-was that?; gadflies; zimbs; and clegs.

Before you go out and buy cans of spray, wait a minute, please. First, be sure the goop you plan on using doesn't cause you more problems than a little loss of a blood.

Unfortunately, horseflies are the vectors for a few nasty diseases that can infect both humans and livestock. But I'm a tough old buzzard, so I allowed that female above to do her thing, hoping she wasn't carrying the parasitic filarial worm from some other human to me.

After all, the Tabanids have their place in the overall scheme of things, just like you and me.

By the same token, there are some horseflies carrying a nasty blood-borne disease that could infect horses: an equine anaemia virus. But even at that, please be cautious with the chemicals you use on your horses.

In spite of the bothersome bites and possibility of sharing disease, a close-up look of an adult horsefly always gives me a thrill. The polarized light of the pigments in her multifaceted eyes is beautiful. The surgical mouth part-sharper than anything man can manufacture - slices through the skin on man and beast so slick you can't feel it - until she goes in deeper to hit nerves, and starts pumping the painful anticoagulants into your blood stream.

One way you can separate horseflies from deerflies is the way a horsefly sneaks up silently on you and jabs her proboscis into your posterior for a blood meal, while deerflies are usually very noisy "buzzers" in flight.

Even the larva (maggots if you will) are predators. Entomologists say some lay their eggs in or near water, where, when hatched, they go after aquatic invertebrates. It's a dog-eat-dog world for all the blood-suckers in the world of survival.

But all's not peaches and cream for the adult horseflies, there's a few broconid wasps that parasitize them, and also a "horse-guard wasp" that attacks horseflies. That's another important reason you have to look before you squirt insecticides; you can often end up killing your friends.