THE SYRPHUS FLIES 



(Family SyrpJiidce.) 



The syrphus flies (for they have no other vernacular name), 

 comprise many of the most interesting of the dipterous insects. 

 It is a very large family and more than three hundred species are 

 known to occur in the United States. As a rule they are rather 

 stout-bodied flies, varying greatly in color. Some are metallic 

 greenish as in Microdon and Psilota, while others are banded with 

 yellow in different ways. As a rule the abdomens are rather broad 

 and are rather apt to be flat, but in some, as in Baccha and its 

 allies, the abdomen is slender. The syrphus flies are flower flies 



Fig. 82. — Mesograpta polita: a, larva; b, puparium; c, adult. 

 (From Insect Life.) 



par excellence. They fly in the sunlight and are easily taken by 

 sweeping flowering plants. Almost all types of bees and wasps 

 are mimicked by them and so generally does this occur through- 

 out the family that syrphus flies form the most striking instances 

 of protective mimicry. There are syrphus flies like honey bees, 

 bumblebees, social wasps and solitary wasps of several kinds. 

 They are rarely to be seen except in the middle of sunshiny days, 

 some of them resting occasionally upon leaves, but more fre- 

 quently they are to be found about flowers, while others seem to 

 be almost constantly upon the wing. 



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