The Two-winged Flies 



32] 



and that one containing the largest flies in the whole f er s he fam, y 

 Tipulida;, whose long-legged, narrow-winged members are fam>harl> knmvn as 

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

 o'-leg flies, which have wings, should not be confused w.th the often sim.- 

 larh- named harvestmen, which are allies of the spiders, have no wmgs, and 

 have four instead of three pairs of legs. The Tipul id legs are extremely 

 ragile, breaking otT at a touch. Most slender-bodied long and thin-legged 

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

 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 \'- , . r a,, c,-,,, 



,_ J 1 f..,i„r-^\ nn thp Fig. 448.— Diagram of wing of crane-fly, i>im- 



shaped mark (suture) on the pucta sv-, showing venation, 



back of the thora.x. More than 



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

 are common all over the countrv, 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 eg-'s are laid in the ground at the bases of grasses and pasture plants, 

 or, bv some species, in mud or slime. The footless, worm-like, dirty-wh.te 

 larvK feed on decaving vegetable matter, fungi, or on the roots or leaves ot 

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

 ^ The largest Tipuhd, 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 nearlv 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 

 larva; (Fig. 450) lie in this shmv 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-hke 

 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 pupa; (Fig. 45°), ^^hich are provided with a pair of 

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

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

 the stream bank. 



