The Two-winged Flies 



321 



and that one containing the largest flies in the whole order, is the family 

 Tipulidae, whose long-legged, narrow- winged members are familiarly known as 

 crane-flies, leather- jackets, and " granddaddy-long-legs. " The granddaddy- 

 long-leg flies, which have wings, should not be confused with the often simi- 

 larly named harvestmen^ which are allies of the spiders, have no wings, and 

 have four instead of three pairs of legs. The Tipulid legs are extremely 

 fragile, breaking off at a touch. Most slender-bodied, long- and thin-legged, 

 two-winged insects of more than one-half-inch length of body are Tipulids. 

 There are some smaller species, 

 however, which might be mis- 

 taken for midges or mos- 

 quitoes, were it not that all 

 Tipulids bear a distinct V- 

 shaped mark (suture) on the 

 back of the thorax. More than 



FIG. 448. Diagram of wing of crane-fly, Sint- 

 plecta sp., showing venation. 



three hundred species of this family are known in the United States, and they 

 are common all over the country, in meadows, pastures, along roadsides, 

 stream-banks, and in woods. The flight is uneven, slow, and weak, and 

 the ungainly flies with their long middle and hind legs training out behind, 

 and the front legs held angularly projecting in front, are unmistakable 

 when seen in the air. 



The eggs are laid in the ground at the bases of grasses and pasture plants, 

 or, by some species, in mud or slime. The footless, worm-like, dirty-white 

 larvae feed on decaying vegetable matter, fungi, or on the roots or leaves of 

 green plants. The root-feeders do some damage to meadows and pastures. 



The largest Tipulid, and the largest species in the whole order of flies, is 

 the giant crane-fly, Holorusia rubiginosa (Fig. 449), common in California. 

 Its body is nearly two inches long, and its legs are from two to two and one- 

 half inches long, so that the spread of legs is four inches. The eggs are 

 laid in the ooze of wet banks of little streams where fallen leaves are decay- 

 ing and subdrainage water is always slowly trickling out from the soil. The 

 larvae (Fig. 450) lie in this slimy bed, in crevices or on narrow ledges of rock, 

 with the posterior tip of the body bearing the two breathing-openings (spi- 

 racles) held at the surface. The soft ooze, composed of soil and slowly 

 decomposing leaves, is swallowed, and, as it passes through the alimentary 

 canal, the organic material digested out of it. The footless, worm-like 

 larvae grow to be two and one-half inches long, but can contract to less than 

 an inch. The duration of the larval life is not yet known, but it is at least 

 several months. The pupae (Fig. 450), which are provided with a pair of 

 long, slender respiratory horns on the prothorax, lie motionless in the slime 

 for twelve days, when the great flies emerge and fly up into the foliage of 

 the stream bank. 



