250 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



1937, Prison & Ross, S $. ZiON, Dead 

 River: July 7, 1937. Prison & Ross, $ $ ; 

 May 23, 1938. Ross & Burks, 2 larvae and 

 cases; June 3, 1938, Mohr & Burks, $ $ ; 

 Tune 4, 1938, Ross & Burks, <? <? , 5 9 ; Aug. 

 "l5, 1938, Ross & Burks, 1 ? ; Aug. 19, 1939, 

 Mohr & Riegel, 1 9 ; May 20, 1940, Mohr 

 & Burks. 2 larvae; June 28, 1940, Mohr & 

 Riegel, 1 larva, 1 pupa, 1 9 ; June 5, 1941, 

 Mohr & Burks, 4 5, 3 9. 



females collected at Eichorn, June 13, 1934, 

 along Hicks Branch, DeLong & Ross. The 

 only records which have come to our atten- 

 tion since that time are a male from Prank- 

 lin County, Ohio, and a female from Broken 

 Bow, Oklahoma. 



Triaenodes phalacris Ross 



Triaenodes phalacris Ross (1938^, p. 88); 



Triaenodes perna Ross 



Triaenodes perna Ross (1938«, p. 159); cf, 



Not yet taken in Illinois. It is known 

 from Athens, Ohio, and may ultimately be 

 taken in southern Illinois. 



Larva. — Unknown. 



Adults. — Length 9 mm. Color tawny, 

 front wing with a definite pattern of cream 

 color and brown; in repose the insect has a 

 dorsal light stripe, a large light area along 

 middle of front margin of wings, a dark 

 brown area across wing at stigma, and a 

 golden brown area beyond this along the api- 

 cal margin. Male genitalia, fig. 844: tenth 

 tergite long and hairlike with a slight thick- 

 ening at apex; beneath this there is a long, 

 membranous, curved process extending be- 

 yond the tenth tergite, claspers flat, the ven- 

 tral aspect somewhat triangular, and the 

 apico-mesal side with a row of black spines ; 

 basal whiplike processes of claspers very 

 long, the right one convoluted and bladelike, 

 the left one filamentous. Pemale genitalia, 

 fig. 854: apex of ninth sternite forming a 

 somewhat anvil-shaped projecting body with 

 flat apical plates; these plates, from ventral 

 aspect, appearing to form a sort of "hat" 

 at the end of the anvil; most conspicuous is 

 the very long internal apodeme of the tenth 

 segment; this apodeme extends almost to 

 the sixth segment, reaching far past the 

 bursa, and has a definite enlarged central 

 portion where it makes a sharp bend; bursa 

 copulatrix short and inconspicuous, its apex 

 terminating in indefinite membranous folds. 



Our Illinois specimens of this species are 

 confined to the type series of a male and two 



Triaenodes tarda Milne 



Triaenodes marginata tarda Milne (1934, p. 

 12); cf. 



Triaenodes vorhiesi Betten (1934, p. 286); 

 cf , 9. New synonymy. 



Triaenodes mephita Milne (1936, p. 59); 

 cf , 9. New synonymy. 



Larva. — Pig. 835. Length 10 mm. Scle- 

 rites straw color, the head with a definite 

 pattern of small spots; the spots along the 

 frons may be sharply coalesced to form an 

 interrupted line. Case as in fig. 862. 



Adults. — Length 12-13 mm. Color taw- 

 ny with the same conspicuous cream and 

 brown pattern as in fig. 863 ; in most speci- 

 mens the dorsal stripe is divided into an 

 elongate anterior area and a posterior dia- 

 mond-shaped area. Male genitalia, fig. 849: 

 tenth tergite long and fusiform ; cerci fairly 

 short and lanceolate ; claspers with base 

 bulbous, lateral angle produced into a long, 

 sharp point, mesal portion produced into a 

 knobbed lobe set with short, stout setae; 

 aedeagus U-shaped and cleft at apex. Fe- 

 male genitalia, fig. 861, with apodemes 

 entirely membranous, ninth sternite some- 

 what anvil shaped, its apical flanges not 

 greatly produced on the meson. 



This species is widely distributed in Illi- 

 nois, occurring in both lakes and streams. 

 We have taken it in abundance, however, 



Fig. 862. — Triaenodes tarda, case. 



