Insect guide > Flies > Crane Flies

Crane Flies

(Family Tipulidae.)
The big slender long-necked flies, commonly known as "crane flies" in this country and as "daddy-long-legs" in England, form a distinct and characteristic group of flies. They have long antennae and very long slender legs which are so slightly attached that it is difficult to capture a Tipulid without breaking one or more of them. The thorax has a V-shaped suture on the back and the wings contain numerous veins and usually a perfect discal cell.

Crane flies are frequently taken for big mosquitoes, but they differ entirely in habits and do not bite, although those of the genus Elephantomyia have a long proboscis, even longer than that of a mosquito. The larvae of most species live in the earth but some live in water, in decomposing wood and even upon the leaves of plants. Some of the earth-inhabiting forms destroy grass and grain by injuring the roots. They breathe through two anal spiracles which in aquatic species are placed at the tip of a long process. The pupal stigmatic tube is set anteriorly, the same change from the anal end to the head end taking place in the transformation to pupa as occurs with the mosquitoes. The pupa itself resembles somewhat a Lepidopterous pupa.

The adult flies are commonly seen in the late summer and are found in pastures and woods, sometimes, especially with the smaller species, swarming towards sundown. More than one thousand species are known and about three hundred of them occur in the United States. Certain forms appear in the early spring and there is a curious wingless genus - Chionea - the species of which are found upon the snow.

The wings of the crane flies are generally clear but are sometimes beautifully marked and spotted as in Limnobia and Tipula. The large and beautiful Pedicia albivittata Walk has striking brown bands on a white wing surface. It is found in the White mountains and the Catskill mountains, as well as in the far north­west and in Alaska. Bittacomorpha with its short wings and banded legs and swollen feet is a most striking form. The California genus Holorusia contains the giants of the family and H. grandis has a wing spread of more than three inches.

The colors of the crane flies are usually dull, but in Ctenophora the body is frequently brilliantly marked with red. In this genus the abdomen is pointed so as to resemble the ovipositor of some Hymenopterous insects and the male abdomen is swollen at the tip almost like that of one of the socalled " Scorpion flies" of the family Panorpidae (q.v.).

Life History of a Crane Fly
(BittacoinoYplacz clavipes Fab.)
Comparatively few species of this family have been carefully studied, but in his important paper on the "Entomology of the Illinois River and Adjacent Waters", Mr. C. A. Hart records some interesting facts concerning this species. The genus Bittacomorpha is found exclusively in America and the larvae of the insect under consideration were found in the early spring in a shallow swampy slough full of rushes and swamp grass. In the mass of dead stems, grass and leaves, through which a broad stream of water ran slowly, were found the cylindrical rusty­brown larvae of Bittacomorpha, which in their appearance look like bits of decaying grass stem.

Their stomachs were found to be filled with diatoms, rnud and dead vegetable tissue and the larvae had evidently fed on the diatomaceous growth which coated the decaying stems. At the anal end of the body was a long respiratory tube bearing two pairs of spiracles at the end.

About the end of March they showed some swelling and within the loose skin the soft white pupae were found. The thoracic respiratory tube was rudimentary and the tube was coiled between the larval and pupal skins. On April 6th the first adult flies issued. Later, in September, a number of adults were seen flying, which indicates either an emergence of the same generation both in fall and spring or two generations annually, the offspring of the fall flies remaining in the larval state through the winter and giving forth adults in the spring. The eggs have not been ob­served and a more careful study of this species is needed.