NO. I BLACK FLIES OF GUATEMALA — DALMAT 75 



ment 7.4 : i ; cornuae of buccopharyngeal apparatus narrowly triangular in 

 shape, very slightly sclerotized ivrighti Vargas, Martinez, and Diaz 



SUBGENERA OF THE GENUS SIMULIUM, BASED ON FEMALE CHARACTERS 



1. Fronto-ocular triangle absent Notolepria Enderlein, 1930 



(Simulium (N.) exiguum Roubaud*) 

 Fronto-ocular triangle present 2 



2. Median space of buccopharyngeal apparatus with two long projections com- 



posed of verj' long teeth; median space with a total of approximately 23 

 well-defined teeth in regular pattern, all but those forming the projections 



in a single row Byssodon Enderlein, 1925 



{Simidium (B.) benjamini Dalmat *) 



Median space without long projections; if numerous teeth are present, they 



are arranged in several rows and are never very long 3 



3. Claw of hind tarsus without well-defined heel, with or without tooth. 



Lanca Vargas, Martinez, and Diaz, 1946 



Qaw of hind tarsus always with well-developed heels ; claw with secondary 



tooth (or projection), the heel extended to form secondary spur, or with 



both tooth (or projection) and secondary spur 4 



4. Ovipositor longer than wide, well developed, lance-shaped. 



Dyarella Vargas, Martinez, and Diaz, 1946 

 Ovipositor usually shorter than wide ; when long, not lance-shaped 5 



5. Genital rod with basal dilatation ; postnotum usually without scalelike hairs, 



when present (S. cfhclae), the pilosity on the frons, clypeus, and occipital 

 region is black and there are white-pruinose longitudinal bands on the 



mesonotum Hearlea Rubzov, 1940 



Genital rod without basal dilatation ; postnotum with a number of yellow, ap- 

 pressed, scalelike hairs ; pilosity on frons, clypeus, and occipital region com- 

 posed of either yellow scalelike hairs or yellow, erect, longer hairs ; meso- 

 notum without white-pruinose longitudinal bands. 



Eusimulium Roubaud, 1906 

 {Simulium (E.) aureum (Fries)*) 



SPECIES OF THE SUBGENUS DYARELLA, BASED ON FEMALE CHARACTERS 



1. Mesonotum with longitudinal bands of white pruinosity 5 



Mesonotum without these white-pruinose longitudinal bands 2 



2. Ri pilose on its distal half to three-fifths ; base color of mesonotum brown 3 



Ri completely pilose ; base color of mesonotum black 4 



3. Base color of mesonotum light brown, with silvery-white scalelike hairs, these 



in groups of 2 or 3 on anterior margin ; Sc usually completely pilose, or, at 

 most, with 1-2 hairs lacking at apical end ; spicules on Ri appear the same 

 as on other veins and on wing membrane in general ; median space of bucco- 

 pharyngeal apparatus with several wide, scalelike teeth. 



earlei Vargas, Martinez, and Diaz 

 Base color of mesonotum dark reddish brown, with golden-yellow scalelike 

 hairs, never in groups ; Sc pilose on basal fourth only ; spicules on Ri some- 

 what larger and more concentrated than on other veins or on wing mem- 

 brane ; median space of buccopharyngeal apparatus smooth, without teeth. 



ardent Dalmat 



