NO. I BLACK FLIES OF GUATEMALA DALMAT 85 



out ventral tubercles Notolepria Enderlein, 1930 



(Simulium (N.) ^.W^rMwrn Roubaud*) 

 Rectal scales usually absent, when present (in S. (L.) callidum), posterior 

 sucker has approximately 105 rows of hooks; eighth segment usually with 

 ventral tubercles (exception: S. (L.) dugesi). 



Lanea Vargas, Martinez, and Diaz, 1946 



SPECIES OF THE GENUS CNEPHIA, BASED ON LARVAL CHARACTERS 



1. Mandibles with 29-32 teeth along inner edge; submentum with 6 hairs in 



ventrolateral row and with 15 toothlike indentations along lateral edge; 



posterior sucker with 95-100 rows of hooks roblesi (De Leon) 



Mandibles with fewer than 29 teeth along inner edge 2 



2. Mandibles with 25 teeth on inner edge ; submentum with 8 toothlike indenta- 



tions along lateral edge ; mouth brushes with 25 branches ; posterior sucker 



with 80-82 rows of hooks pacheco-limai (De Leon) 



Mandibles with 23 teeth on inner edge ; submentum with 6 toothlike indenta- 

 tions along lateral edge ; mouth brushes with 30-35 branches ; posterior 

 sucker with 72-75 rows of hooks agnirrei Dalmat 



SPECIES OF THE GENUS GIGANTODAX, BASED ON LARVAL CHARACTERS 



Posterior sucker with 95-105 rows of hooks; cephalic fan with 26-30 branches; 

 mandible with 9 or 10 teeth on inner edge, the first 2 of these being completely 

 separated from each other and the second well removed from the third; pair 

 of cone-shaped tubercles on ventral surface of segment 8 ; rectal scales present, 

 arranged in 4 or 5 irregular rows; anterior arms of anal sclerite (X-shaped) 

 expanded anteriorly to form heart-shaped structure. 



wrighti Vargas, Martinez, and Diaz 



Posterior sucker with 126-134 rows of hooks ; cephalic fan with 34-40 branches ; 

 mandible with 11 teeth on inner edge, the first being contiguous to the second 

 which appears to arise from the same base as the third; no cone-shaped tuber- 

 cles on ventral surface of eighth segment ; rectal scales absent ; anterior arms of 

 anal sclerite (X-shaped) not expanded anteriorly; well-sclerotized triangular 

 patch on either side between the anterior and posterior arms. 



aquamarensis (DeLeon) 



SPECIES OF THE SUBGENUS DYARELLA, BASED ON LARVAL CHARACTERS 



1. Posterior sucker with more than 300 rows of hooks 2 



Posterior sucker with fewer than 300 rows of hooks 3 



2. Rectal scales present ; posterior sucker with 450-460 rows of hooks ; anal gills 



with 57 branches ; frons-clypeus extremely dark brown, so dark that mark- 

 ings are scarcely visible smarti Vargas 



Rectal scales absent ; posterior sucker with 350-360 rows of hooks ; anal gills 

 with 36 branches ; frons-clypeus light orange with 4 dark-brown longitudinal 

 patches in form of cross acatcnangoensis Dalmat 



3. Posterior sucker with 150-156 rows of hooks; anal gills usually with 10 



branches pitlvernlentum Knab 



Posterior sucker with more than 200 rows of hooks ; anal gills with more than 

 20 branches 4 



