78 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



Median space of buccopharyngeal apparatus serrated, with a single large cen- 

 tral tooth ; claw of posterior leg with subbasal tooth. 



jacumbae Dyar and Shannon 



4. Mesonotum with yellow scalelike hairs tricornis De Leon 



Mesonotum without yellow scalelike hairs 5 



5. Band of white pruinosity around entire periphery of mesonotum, in addition to 



white-pruinose longitudinal bands or stripes ; Ri with spines and hairs along 



its distal half jobbinsi Vargas, Martinez, and Diaz 



Anterior margin of mesonotum not completely white-pruinose ; Ri with spines 

 only along its distal half metallicum Bellardi 



species of the subgenus simulium, based on female characters 



(alternate key) 



1. Genital rod with basal dilatation 2 



Genital rod not expanded basally 5 



2. Basal dilatation small, triangular jacumbae Dyar and Shannon 



Basal dilatation more extensive, oval 3 



3. Mesonotum orange yellow; ovipositor longer than wide, not triangular in 



shape ochraceum Walker 



Mesonotum black ; ovipositor wider than long 4 



4. Expansions of genital fork with two triangular-shaped structures near mid- 



region and with apices pointed kompi Dalmat 



Expansions of genital fork without triangular-shaped structures, the apices 

 not pointed jobbinsi Vargas, Martinez, and Diaz 



5. Median space of buccopharyngeal apparatus with 4 rows of wide, blunt teeth. 



parrai Vargas, Martinez, and Diaz 

 Median space hyaline and smooth, without teeth 6 



6. Mesonotum with long, narrow, yellow, scalelike hairs, denser on anterior 



fourth tricornis De Leon 



Mesonotum without scalelike hairs metallicum Bellardi 



GENERA OF SIMULIIDAE, BASED ON PUPAL CHARACTERS 



I. Posterior extremity of pupa with prominent spines (terminal spines) ; 3-7 

 simple to trifid hairs on either side of ventral surface of ninth abdominal 

 segment ; ventral surfaces of abdominal segments 5-7 with at least 4 spines, 

 always simple ; ventral surfaces of all abdominal segments with granulosity ; 

 cocoon soft, composed of a very loose network of threads, attached to sub- 

 stratum along at least 80 percent of its base 2 



Spines at posterior extremity of pupa very small or absent ; at most, one short, 

 simple hair on either side of ventral surface of ninth abdominal segment; 

 ventral surfaces of abdominal segments 5-7 with a maximum of 4 spines : 

 simple, bifid, trifid, or in combination ; when all these spines are simple, those 

 on segment 5 are closer together than those on segments 6 or 7 ; ventral sur- 

 faces of abdominal segments lacking granulosity ; cocoon of firmer texture, 

 the threads, when visible, are held together in a parchmentlike matrix; 

 cocoon attached to substratum along a maximum of only 60 percent of 

 its base Simulium Latreille, 1802 



