NO, I BLACK FLIES OF GUATEMALA — DALMAT 273 



SIMULIUM (HEARLEA) NIGRICORNIS Dalmat 



SimuHum (Hearlca) nigricornis Dalmat, Ann. Ent. Soc. Amer., vol. 43, No. I, 

 pp. 148-151, figs. 15-20, 1950(b) (original description, d* genitalia, ? head and 

 genitalia, and pupa). 



Male (pi. 27, figs. 115-117). — Only genitalia available. 



Genitalia: Sidepiece (pi. 27, fig. 115) broader than long with 

 extremely prominent dome-shaped extension from the inner, posterior 

 corner of the dorsal surface ; extension so pronounced that it gives the 

 sidepiece an appearance of being pentagonal. Clasper (pi. 27, fig, 115) 

 long and narrow, with well-developed apical spine arising from short 

 longitudinal furrow near its apex. Adminiculum (pi. 27, fig. 116) 

 with main body broader than long; general shape quadrangular with 

 all margins rounded ; basal processes broad, pointed at apex, heavily 

 sclerotized throughout, equal in length to the body of the adminicu- 

 lum ; apical margin of adminiculum in the form of two rounded, lateral 

 expansions, between which projects a median, fingerlike extension 

 clothed with curled hairs ; on the ventral surface of the adminiculum, 

 extending anteriorly from the median prolongation, there is a moder- 

 ately pronounced keel which reaches the anterior margin ; keel with 

 row of hairs on both edges ; strong, stout spine present on each side 

 of ventral surface. Adminicular arm (pi. 27, fig. 117) heavily sclero- 

 tized, with 2 semicircular, hyaline, chitinized processes near its at- 

 tachment to the lateral plate and 3 rather blunt teeth at its distal end ; 

 lateral plate hyaline, without wrinkles, triangular in shape. 



Female (pi. 34, figs. 235 and 236). — Only head and genitalia 

 available. 



Head: Dichoptic. Antenna 11 -segmented, not strongly tapered, 

 the third segment equal in length to the fourth and fifth measured 

 together. Buccopharyngeal apparatus simple, the lateral processes 

 well sclerotized, and with a definite indentation in the margin of the 

 inner space. Base of f ronto-ocular triangle i .5 times its height. 



Genitalia: Cercus (pi. 34, fig. 235) quadrangular, higher than 

 long (broad), clothed with numerous spines and with minute, ap- 

 pressed hairs. Anal lobe (pi. 34, fig. 235) elongate, extending ventrad 

 beyond the ventral border of the cercus ; with minute, appressed hairs 

 over entire surface and stout spines distributed sparsely only on ven- 

 tral half ; anterior ventral angle clothed with numerous fine hairs. 

 Genital rod (pi. 34, fig. 236) with apical expansions triangular, only 

 the external basal angle rather heavily sclerotized and pointed. 



Pupa (pi. 38, fig. 315, and pi. 39, fig. 355). — Granulosity on entire 

 thorax; 2 very thin, simple trichomes on either side of midline of 

 thorax. Dorsal surface of abdominal segments: No granulosity; 



