3 (2). Dorsal side of head with largely blackish, flattened tubercles; spots 



of pronotum of irregular form, lateral spots smaller than median 

 spot; the Caucasus 2. S. proximus Mart. (p. 425) 



4 (l). Head lighter, yellowish gray or brownish; pronotum without large, 



light epots; European species, possibly occurring on western 



border of the USSR 3. S. nigricornis Pict. (p. 428) 



1. Silo pallipes Fabrizius* 



McLachlan, 1865:82—83.- Thienemann, 1905b:522, Figures 35—37.— 

 Siltala, 1905:15-19, Figure 4; 1907:533-565.- Lestage, 1921:849-856, 

 Figures 305, b, h, 306, 307.- Hickin, 1942:123-126, Figures 1-9.- Nielsen, 

 1942:588, 607, 615.- Baker, 1963:171-174, Figure 3.- Brindle, 1964:197. 



Full-grown larva. Length 7—8 mm. Head mainly dark, with a large, 

 dark, reddish spot from one eye to the other, including flat median area 



333 (Figure 575). Frontoclypeus with small, light tubercles anteriorly in the 

 middle, with larger, brownish tubercles laterally; median area short 

 between anterior frontal seta and tentorial pit, forming a dark, transverse 

 stripe with a dense cover of large, flattened, reddish brown tubercles, and 

 raised ridgelike above flat area of anterior part and entire posterior part; 

 posterior part of frontoclypeus reddish brown, with large, flat tubercles 

 anteriorly, wedge-shaped pattern replaced by light dots. Area lateral to 

 frontal suture dark, covered with large, flattened tubercles, and with smooth, 

 light chestnut brown parts without tubercles; periocular ridge narrow, 

 comblike, dark, densely covered with small, rounded tubercles. Ventral 

 surface light, reticulate, slightly grayish in middle, with a large, smooth 

 area w^ith vague whitish dots near occipital foramen. Gula long, triangular, 

 brownish, with light, indistinct posterior part; pregula brown, divided from 

 gula by a dark stripe, its anterior margin with a deep median indentation. 



Intermediate anterior-margin seta dark brown, thick, moderately long; 

 median anterior-margin seta shorter, dark, thick; lateral anterior-margin 

 seta short, light, curved inward; anterior frontal seta small, brown, 

 contrary to usual, much smaller than lateral anterior-margin seta; inter- 

 mediate frontal seta similar, situated slightly anterior to tentorial pit; 

 posterior frontal seta very small. Seta 7 strong, dark brown, moderately 

 long, shorter and thinner than median anterior-margin seta; seta 9 short, 

 thick, brown, anterior and lateral to ridge; seta 10 light, situated before 



334 eye; seta 11 medial to eye; both small, thin; seta 12 situated laterally 

 behind eye, small, light; setae 14 and 15 situated one behind the other, close 

 together, brown, thin, of equal length, shorter than median anterior-margin 

 seta; seta 17 small, brown, thick basally, situated behind fork some distance 

 from suture. Ventral seta 8 short, thin, brown; seta 18 small, light. 



Dorsal sclerite of labrum dark chestnut brown; anterior margin with 

 rounded anterior angle; surface with blunt tubercles, lateral tubercles 

 larger; groove at posterior margin not darker than other surface. 

 Posterior-angle sclerites of labrum thin, curved inward; membranous 

 anterior and anterior lateral parts large, as in Goer a, lobes similar. 

 Light setae 1,2, and 4 as in Go era; setae 5 and 6 large, dark; seta 6 



The literature is not quoted completely as some data are not reliable f see Nielsen, 1942:5^ 



417 



