Localities in which Pellagra is Prevalent 2T 



interesting in this relation, because while some of the gen- 

 era of the family do not sting and cannot be regarded as 

 noxious, some are pests, and may become the source of a 

 good deal of annoyance to people living along streams. The 

 punkie or no-see-em {Ceratopogon nociviim) of northern 

 woods is an example. We have this, or a similar species, in 

 Kentucky, sometimes encountered even about the City 

 Reservoir at Lexington during the first warm spring days, 

 and occasionly within the city limits. Harris says of them 

 (Insects of Massachusetts, 1852): "So small are they that 

 they would hardly be perceived were it not for their wings 

 which are of a whitish color mottled with black. Toward 

 evening these winged atoms come forth and creep under 

 the clothes of the inhabitants, and by their bites produce an 

 intolerable irritation. " m< * * * In my own experience 

 these minute stinging gnats simply sting the moist back of 

 of the hand and show little or no disposition to creep under 

 the clothing. 



Fig. 9.— Larva and case of Tanytarsus from Left Fork of 

 Straight Creek, 1911. X 854. 



The case-making species collected at Gary, Sept. 1, be- 

 longs to the genus Tanytarsus, and may prove to be 

 T. exiguus, of Johannsen, though there are some differences 

 to be accounted for before this can be considered established. 



No. 1. Tanytarsus sp.- Length, 3.5 mm. Translucent, 

 white, the head pale yellow. Cylindrical, the somites some- 

 what thicker anteriorly, segmentation very evident, the 

 body consisting of twelve somites, of which the anterior 

 bears a pair of clawed prolegs and the posterior is truncate 

 and bears two tufts of long black setae on its dorsum, a pair 

 of retractile clawed prolegs on its ventral side and pos- 

 teriorly four lanceolate respiratory appendages. The head 



