503 



the vittae black, very broad ; pleura," largely black ; scutelliim yellow ; 

 postnotiim shining black. Abdomen velvety black, basal segment yel- 

 low, slightly darkened, apices of remaining segments and bases of 

 third and fourth shining yellow; hypopygium yellow. Legs yellow, 

 mid and hind coxte, fore femora except the bases, apices of mid and 

 hind femora, fore tibiae except the middle, both ends of mid and hind 

 tibiae, the entire fore tarsi, apices of basal three joints and whole of 

 apical two of other tarsi blackened. Wings whitish, veins yellow. 

 Halteres pale yellow, base of pedicels blackened. 



Antenna barely longer than head and thorax together. Pronotum 

 broad, of almost equal width throughout. Hypopygium as in Figure 

 4, Plate XXX\'^II. Legs slender ; fore tarsi with rather long hairs ; 

 basal joint slightly more than half as long as fore tibiae (23 : 45) ; sec- 

 ond joint about half as long as basal (12). Wing venation almost 

 identical with that of trifasciatiis. 



Peniale. — Agrees with the male in color except that the dark color 

 on thorax is not so conspicuous, and that on abdomen more generally 

 distributed, though the basal segment is almost entirely yellow. The 

 legs have the black more sharply differentiated from the pale portions 

 and confined to smaller areas. 



Length, 3-5 mm. 



Tvpe locality, Urbana, 111., October 5-9, 19 14, at light (C. A. 

 Hart 'and J. R. Malloch). 



The fore tarsal hairs and distinctively marked abdomen should 

 serve to separate this from every other described American species. 



2. Cricotopus trifasciatus Panzer 



Chironomus trifasciatus Panzer, Fauna Germ., 1813, p. 109. 



Cricotopus trifasciatus (Panzer) V. d. Wulp, Tijdschr. v. Ent., Vol. 17, 1874, 

 p. 132. 



Bgg.—{F\. XXXVni, Fig. 7). Whitish. Deposited in long 

 rope-like masses. 



Larva. — Length, 4-5 mm. Yellow, varying sometimes to red- 

 dish. Head about 1.5 as long as wide; antenna as in Figure 9, Plate 

 XXX ; mandibles with three distinct teeth in addition to the apical 

 one; labium as in Figure 12, Plate XXIX. Abdomen with a pecu- 

 liar tuft of long pale hairs near posterior margin of the lateral sur- 

 face of each segment, which are weak on segments i and 2 ; anal 

 dorsal respiratory organs distinct, four in number, ventral surface 

 without anal blood-gills ; anal pseudopods short, armed at apices with 

 the normal claws. 



