NO. I BLACK FLIES OF GUATEMALA — DALMAT 83 



4. Dorsum of segment 9 with numerous comblike groups of minute spines, and 



with 4-12 larger spines in a transverse row, these divided into two groups 

 by a median space ; cocoon without lateral "wings." 



doivnsi Vargas, Martinez, and Diaz 



Dorsum of ninth segment without comblike groups of minute spines ; cocoon 



normally with lateral "wings" 5 



5. Ninth segment with continuous transverse row of 8 spines, without median 



space ; spines on ventral surface of segment 4 simple samboni Jennings 



Ninth segment with transverse row of 15-18 spines, these divided into two 

 groups by median space ; spines on ventral surface of segment 4 bifid. 



colvini Dalmat 



6. Four arborescent trichoraes on either side of midline of thorax; all respiratory 



filaments arched dorsally, appearing like a fan; dorsal surface of seventh 

 abdominal segment with 0-8 simple spines in transverse row, divided into 

 two groups by median space, and with several minute spines arranged in 



comblike groups callidiim (Dyar and Shannon) 



Two bifid trichomes on either side of thorax ; respiratory filaments not arched 

 or in form of fan; dorsum of seventh abdominal segment with 8-18 spines in 

 transverse row, divided by median space, but with no comblike groups of 

 minute spines haematopotiim Malloch 



7. The filaments of each respiratory apparatus forming a compact group ; usually 



seven trichomes on either side of midline of thorax, 5 bifid and 2 simple; 

 dorsum of eighth abdominal segment with 13-22 simple spines in transverse 

 row, divided into two groups by a median space. 



veracrusamim Vargas, Martinez, and Diaz 

 The filaments of each respiratory apparatus well separated from one another, 

 not in compact groups ; usually 5 simple, hairlike trichomes on either side of 

 midline of thorax, close to lateral margins ; dorsum of eighth abdominal 

 segment with approximately 30 simple spines in an uninterrupted transverse 

 row trivittatum Malloch 



SPECIES OF THE SUBGENUS SIMULIUM, BASED ON PUPAL CHARACTERS 



1. Branches of respiratory apparatus filamentous 2 



Branches of respiratory apparatus tubular, inflated 5 



2. Respiratory apparatus of each side composed of 6 filaments 3 



Respiratory apparatus composed of more than 6 filaments 4 



3. Cocoon with lateral "wings" usually so well developed, the cocoon appears 



circular when viewed from above ; dorsal surface of sixth abdominal seg- 

 ment with S-12 spines in a row, the spines being at irregular intervals and 

 in groups of i, 2, or 3, but without separation near midline; same surface 

 with numerous comblike groups of minute spines lateral to the main row as 



well as between the spines of that row mctalUcinn Bellardi 



Cocoon without lateral "wings" ; dorsal surface of sixth abdominal segment 

 without spines or comblike groups of minute spines. 



jobbinsi Vargas, Martinez, and Diaz 



4. Respiratory apparatus with 8 filaments; dorsum of thorax smooth; all spines 



on dorsal surface of second abdominal segment in straight row; ventral 

 surfaces of segments 6 and 7 each with 4 spines ; margin of anterior aperture 

 of cocoon thickened, without dorsal prolongation ochraccum Walker 



