(3). Anal lobes, especially of female pupae, very short; penis sheath 



short 1. H. picicornis Steph. (p. 500) 



(2). Anal lobes as in the other genera, relatively long, slightly narrower; 



at the end; penis sheath longer than in H. picicornis 



2. H. stagnalis Alb. (p. 508) 



(l). Labrum rounded anteriorly; anterior seta of clypeus much shorter 

 than the other two. Hind tarsi without natatorial setae; conical 

 ventral process of segment 8 of female pupae short, without 

 indentation 3. H. dubius Ramb. (p. 508) 



1. Holocentropus picicornis Stephens 



Struck, 1899:342, Figure 29; 1900:27, Figure 47. - Ulmer, 1901:200-202, 

 Figures 1-8; 1903:120, Figures 79,124.- Struck, 1903:119, Plate IV, 

 Figure 3.- Siltala, 1903c:13; 1905:125-127, Figures 31,32.- Thienemann, 

 1905b:539-540. - Figures 85-87. - Ulmer, 1909:230-231, 297, Figure 355, c.- 

 Lestage, 1921:496-502, Figure 162, c, d, h, i, k. - Lepneva, 1940:205. 



Full-grown larva. Length 14— 16 mm. Head (Figure 637) yellow, with 

 distinct pattern. Frontoclypeus with dark lateral stripes, which are 

 slightly broader anteriorly; stripes smoke brown anteriorly; stripes dark 

 brown and narrow near the curvature of the frontal sutures, with three large 

 dark dots situated behind each other; they are brownish posteriorly, 

 separated by a light space from the dark part of the middle; sclerite light 

 in the middle including the posterior angle; transverse row of dots absent 

 or indistinct posteriorly, consisting of only 1 or 2 lateral dots.* Latero- 

 anterior margin seta transparent, curved inward; intermediate and median 

 seta situated at a distance from the lateral seta; both setae thin; inter- 

 mediate seta relatively long; lateral seta short, situated near the margin; 

 3 dark dots posterior to it; anterior frontal seta thin, short, situated at 

 posterior angle of clypangulus; middle seta situated slightly farther 

 posteriorly, small; posterior frontal seta brownish black, long, situated 

 near suture at end of dark lateral stripe. 



Clypangulus dark brown; brown, dorsal stripes extending from the 

 anterior margin to the occipital foramen, where they become narrow; 

 a light spot between dorsal stripe and frontal suture (at the curvature of 

 442 the suture) remains; small and larger dark dots present in the posterior 

 part along the stripes; lateral stripes also replaced by rows of dots. 

 Groups of dots present ventrally, in the posterior half (Figure 639). Large 

 setae dark brown or blackish brown. Seta 9, the longest seta of the sclerite, 

 situated at margin of dorsal stripe, medial to the eye; seta 11 situated 

 anterior to it, thin, dark and short; seta 7 strong, straight, situated near the 

 margin, slightly thinner and much shorter than seta 9; seta 10 situated 

 lateral to the eye, small and light; long seta 12 and similar but slightly 

 shorter seta 14 situated behind the eye; two setae situated behind each 

 other posteriorly near the dorsal stripe: short, light, thin seta 15 and dark 

 seta 16, which is slightly longer and thicker; seta 17 situated more medially, 



According to Siltala (1905:125— 126, Figure 32) the light form and the typical form of H. picicornis 

 var. a u r a t u s , which occur in the north, have no row of dots in the posterior part of the frontoclypeus; 

 dots are present in the dark form. 



500 



