64 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



fig. 256, or verv little sclerotized, 

 fig. 257 ' 25 



25. Bursa supports distinct, sclerotized, 



slender and sinuate, fig. 256 



elarus, p. 65 



Bursa supports chiefly membranous, 

 with only a small basal portion and 

 a curious sclerotized forklike piece 



near bursa, fig. 257 



confusus, p. 65 



26. Sclerotized bands of ninth tergite 



more rectangular, parallel, and 

 closer together at base, fig. 258. . . . 



maculatus, p. 65 



Sclerotized bands of ninth tergite sinu- 

 ate, pointed at apex, wide apart at 

 base, and converging rapidly to 

 apex, fig. 259 pentus, p. 65 



27. Ninth sternite with a pair of somewhat 



quadrate sclerotized plates pointed 

 at apex; bursa copulatrix not 



heavily sclerotized, fig. 260 



remotus, p. 67 



Ninth sternite without sclerotized 

 plates; bursa copulatrix heavily scle- 

 rotized, fig. 261 cinereus, p. 67 



Polycentropus crassicornis Walker 



Polycentropus crassicornis Walker (1852, p. 

 101); d^, 9. 



Plectrocnemia adironica Banks (1914, p. 

 256); cf. 



Pletrocnemia australis Banks (1907a, p. 131); 

 9. 



Larva. — Unknown. 



Adults. — Length 9-10 mm. Color brovi^n, 

 the front wings irrorate over their entire 

 surface with brown and yellowish spots. 

 Male genitalia, fig. 235: ninth segment 

 produced into a long, pointed tongue which 

 projects to the apex of claspers; cerci short 

 and ovate; claspers very heavily sclerotized, 

 lateral margin narrow, apical margin ex- 

 panded, with a sharp mesal tooth at apex 

 pointed ventrad ; tenth tergite submembra- 

 nous and small ; connecting this and the 

 cerci is a heavily sclerotized plate which is 

 divided at its apex into a pair of heavily 

 sclerotized prongs, one angled sharply 

 dorsad, the other curved ventrad; aedeagus 

 with a tubular base, the apex narrowed 

 and consisting of membranous folds and 

 internal sclerotized rods. Female genitalia, 

 fig. 249, forming a long, tapering, heavily 

 sclerotized structure, divided on the venter 

 by a long, narrow tongue, at the base of 

 which are lateral lobes produced into sharp, 

 long points on their meso-apical corner. 



We have only four Illinois records for 

 this species, two from marsh areas in the 

 extreme northeastern corner of the state 

 (see p. 12), another from the east-central 

 margin and the fourth from the extreme 

 southern portion. Little is known regarding 

 the biology of the species or its habitat 

 preference. It is widespread throughout the 

 eastern United States and Canada, with 

 records from Florida, Illinois, Massachu- 

 setts, Michigan, New York, Ontario and 

 South Dakota. 



Illinois Records. — ^Alto Pass, Union 

 Spring: May 26, 1940, Mohr & Burks, 1 $ . 

 Rosecrans, Des Plaines River: June 9, 

 1938, at light, Ross & Burks, \$ , 1 $ . 

 Urbana: June 1, 1938, light trap, G. T. 

 Riegel, 1^. ZiON, Dead River: June 3, 

 1938, Mohr & Burks, 1 $ . 



Polycentropus aureolus (Banks) 



Plectrocnemia aureola Banks (1930^, p. 130); 

 cf , 9. 



Described from Nova Scotia, this species 

 has been taken also in New Hampshire and 

 Minnesota. It has not yet been taken in 

 Illinois. 



Polycentropus centralis Banks 



Polycentropus centralis Banks (1914, p. 258); 



Larva. — Length 11 mm. Head, pronotum 

 and legs yellow, the head with very indis- 

 tinct spots arranged in the same pattern as 

 in fig. 231; posterior margin of pronotum 

 dark brown. 



Adults. — Length 7-9 mm. General color 

 brown with irregular light areas on the 

 wings and definite pale spots around their 

 border. Male genitalia, fig. 248: cerci 

 stocky, apical filament fairly short; claspers 

 short, the baso-dorsal appendage trapezoi- 

 dal, its inner point sharp and serrulate; 

 aedeagus slightly sinuate but its general out- 

 line straight. Female genitalia, fig. 253 : 

 eighth sternite broad, its apical margin 

 fairly evenly rounded, lateral lobes moder- 

 ately short and pointed at apex ; ninth 

 sternite with two short, broad, rounded 

 lobes; bursa copulatrix porelike, its supports 

 forming a broad base and a pair of fusi- 

 form supports which run close together to 

 give the entire structure' a more or less 

 vasiform appearance. 



