138 SCHOOL ENTOMOLOGY 



of hovering or remaining poised in the air is well devel- 

 oped here but should not lead one to mistake bee-flies, for 

 some of the Syrphidos which have a similar habit. Bee- 

 flies, and certain syrphus-flies as well, mimic some of 

 the bees and wasps. 



90. Snipe-flies (Leptidci), are not of great importance, 

 but may be mentioned because of a few of the more 

 abundant forms. These have bodies shaped like those of 

 mosquitoes but much larger and heavier. The legs are 

 relatively short and the wings, while narrow, are power- 

 ful. One species which is usually common has the top of 

 the thorax clothed with thick orange yellow or golden hairs. 



91. The Syrphus-flies (Syrphidce), as these are com- 

 monly called, are very numerous and have many different 

 forms. They present a greater number of bee-like forms 

 than do the bee-flies themselves. Some resemble bumblebees 

 very closely; others look more like the honey-bee, one species 

 being known as the Drone-fly, on account of the simi- 

 larity. The typical members of the family are of small to 

 medium, or even large size, have flattened and rather broad 

 bodies, and colors usually, at least in part, yellow or green 

 or both. They hover or poise in the air, sometimes over 

 flowers or other food, more often apparently over noth- 

 ing in particular. Some species bite animals and man and 

 are called Sweat-flies. They are often confused with sweat- 

 bees, which are, properly, true bees and sting, while the 

 sweat-flies pierce the skin with their mouth-parts. The 

 wound from the fly bleeds slightly, while the bee sting 

 does not. Larvae of syrphus-flies are, many of them, 

 predaceous, feeding on plant lice. These larvae have bodies 

 tapering toward the heads, slightly flattened and scalloped 

 along the margins. They may be green with yellow mark- 

 ings. Other syrphus-fly larvae are entirely different. The 



