August, 1944 



Ross: Caddis Flies of Illinois 



203 



The genus is represented in the eastern 

 states by many species, but we have taken 

 only one in Illinois. Two others occur in 

 nearby states and have been included in the 

 key. 



The biology of the genus in this latitude 

 is unique in having a long aestivation period, 

 the larvae usually maturing early in the 

 spring, and the adults emerging late in 

 autumn. All three species treated here have 

 been reared, but no satisfactory key charac- 

 ters have been found to separate the larvae. 



KEY TO SPECIES 

 Adults 



1. Maxillary palpi 3-segmented (males) 2 

 Maxillary palpi 5-segmented (females) 4 



2. Claspers with a long, curved, heavily 



sclerotized mesal arm, fig. 697 



autumnus, p. 203 



Claspers without a heavily sclerotized 

 arm, at most with a mesal flange as 

 in fig. 698 3 



3. Claspers long, wide apart at base, with 



a mesal flange, fig. 698; ninth ster- 



nite slightly incised on meson 



ayanus, p. 205 



Claspers short, close together, without 

 a mesal flange, fig. 699; ninth ster- 

 nite with a short, truncate mesal 

 projection fuscus, p. 205 



4. Subgenital plate with 2 pairs of promi- 



nent lobes, fig. 700. . .autumnus, p. 203 

 Subgenital plate with a mesal, spatu- 

 late style and a pair of low, lateral 



lobes, fig. 701 



fuscus, p. 205; ayanus, p. 205 



Neophylax autumnus Vorhies 



Neophylax autumnus Vorhies (1909, p. 669); 

 d, 9, larva. 



Larva. — Length 8-9 mm. Head varying 

 from reddish brown to blackish brown, 

 sometimes with a paler mesal stripe and 

 always with round pale spots on dorsal por- 

 tion. Thoracic sclerites and legs brownish 

 yellow with narrow black areas along some 

 sutures. Head long, malar space twice as 

 long as distance from eye to top of head; 

 upper portion of frons produced into a low 

 but definite hump; antennae situated on a 

 slight protuberance. All legs the same shape, 

 the front ones only slightly modified for 

 grasping. Pronotum velvety and produced 

 into a rounded anterior portion under which 

 the head may be retracted. Gills single and 



short. Sternites 3, 4 and 5 with an oval 

 sclerotized ring. 



Case. — Length 8-10 mm. Constructed of 

 stones, slightly curved, nearly cylindrical, 

 with larger stones situated along each side 

 to give it a broadened appearance. Before 

 aestivation, the anterior portion of the case 

 is capped with a single flat stone, around 

 the edge of which are small vents. 



Adults.— Fig. 702. Length 9-12 mm. 

 Head and body brownish yellow; front 

 wings fairly dark brown with irregular, 

 small, lighter areas scattered over most of 



FUSCUS 



699 C 



Figs. 697-699. — Neophylax, male genitalia. 

 A, B and C, respectively ventral, lateral and 

 caudal aspects. 



