FLIES, MOSQUITOES, AND MIDGES 



227 



appear in immense numbers. The larvae are found attached to 

 rocks in shallow, swift-flowing streams, where they feed on various 

 minute plants and bits of vegetation. The adult flies are about one 

 fifth of an inch long, stout-bodied, blackish, with short legs and an- 

 tennae, though the antennae have many distinct segments. Recent 

 experiments made in the White Mountains indicate that it may be 

 possible to eradicate the larvae in mountain resort regions by oiling 

 the streams with Phinotas oil. The southern buffalo gnat is a 

 serious pest of domestic animals in the South, such immense 

 swarms sometimes appearing as to cause their death. 



FIG. 358. The pine-cone willow gall caused by a cecidomyiid, cut open at 



right to show maggots within 



(After \Vashburn) 



Fungus-gnats. Wherever there is decaying vegetable matter 

 or damp fungi, as in decaying wood, under damp bark, in decom- 

 posing leaves, etc., there are found small, white or pink maggots, 

 which develop into the graceful little fungus-gnats (Mycetophilidae]. 

 The larvae often stick together in large patches, and sometimes 

 form long processions of wriggling maggots. One species feeds on 

 injured apples, while another has been shown to cause a form of 

 potato scab, and one is a serious pest of mushrooms, but most of the 

 larvae are entirely harmless. The flies are mosquitolike in general 

 form, but the antennae are bare and the coxae are unusually long. 



