One of the first insects to arrive indoors with the longer spring days is the Crane Fly. Its large, clear wings, delicate, gangly legs and erratic flight call attention to it from anywhere in a room. The fact that it also resembles a giant mosquito certainly helps it get noticed. Out of nowhere, one or more can show up near a lamp, a window or mirror as if trying to show themselves off to their full advantage.

In a way, people who regard them as giant mosquitoes aren't too far off. Crane flies are the largest insects in the order, Diptera, the flies, an order which includes the mosquitoes. Crane flies evolved some 200 million years ago in the age of the dinosaurs, and some of their primitive relations still survive. They are close relatives of the mosquitoes, and like them, crane flies have only two wings, a thin elongated body, and very long legs. Crane flies make up their own family, Tipulidae, and within this family some 6000 species are described worldwide, of which some 400 are found in California.

The Giant Crane Fly, Holorusia rubiginosa, is one species that lives in our area and is actually one of the largest flies in the world, with a wingspan, or at least a legspan, that can reach across your palm. These are mostly found in wetter areas, often near streams. The "Common crane flies" include several species which make up the genus Tipula and which are found in the grassland and damper forest habitats that California offers. These insects are still quite large, half an inch in body length alone, and are the more common indoor visitors that test those with mosquito phobia.

I was instructed as a younger naturalist to leave Crane Flies alone. One reason was obvious. If you try to catch one, it falls apart in your hands. Its giant legs practically fall off when they are touched. Standing with one or more legs in your hands, a child who then faces the remainder of this giant insect fluttering around is understandably alarmed.

The other reason for leaving them alone was perhaps more strange. I was told these giant insects that look like huge mosquitoes, and that fly around without an apparent sense of purpose or rudder, were supposed to hunt down and eat mosquitoes. They were "mosquito eaters". Unfortunately, this potentially valuable idea about the crane fly as a top predator in the drama of an indoor Serengetti isn't true. They don't even like blood.

To put the rumor to rest, Crane flies are for the most part vegetarians. They haven't developed the mouth parts that mosquitoes use to access animal blood. In their larval form some species may eat roots or stems, or small invertebrates in the case of some aquatic species, while many species eat decaying plant matter. This is not all good news, as the larvae of one native species, the Range Crane Fly, tipula simplex, along with another non-native European species can damage grasses and grain crops. Mostly though, they are harmless or even helpful. They are food for fish, birds and other insect eaters, and of the many that eat decaying plant matter, their work in turn helps make soil that supports plant life, which in turn feeds animal life. It is interesting how many things including crane flies are linked together to make the complex web of life that supports all of us.

Near to their food source, crane fly larvae can be found in water to damp vegetation to soil. Larvae are often called "leather jackets", because in some species they have a tough, grey, brown or black covering.

Apparently, little is known about the eating habits of adult crane flies. What is known is that they fly about in what appears as an awkward motion, trailing their rear leg pairs behind them, looking like an obvious meal for a predator. These habits suggest to at least one naturalist from the Natural History Museum in London that crane flies engage in a courtship display, often as a social activity, and that they have evolved their breakaway legs to compensate for their large size and the courtship patterns that can make them such an easy meal. A would-be predator often winds up with a leg or two, while the adult crane fly can continue relatively unbothered with even two of its six legs missing.

For all the strange things that may bump us in the darkness