NO. I BLACK FLIES OF GUATEMALA — DALMAT 7I 



SPECIES OF THE SUBGENUS DYARELLA, BASED ON EXTERNAL 

 CHARACTERS OF THE MALES 



1. In addition to longitudinal dark lines, mesonotum with longitudinal white- 



pruinose bands, stripes or lines 2 



Mesonotum with dark lines only 6 



2. Longitudinal white-pruinose designs in form of very wide bands, occupying 



most of central region of mesonotum 3 



Longitudinal white-pruinose designs in form of narrow stripes 4 



3. Mesonotum with two extremely wide, longitudinal, white-pruinose bands, each 



about one-quarter the width of scutum, separated by a black line which ends 

 at the prescutellar region; scalelike hairs on mesonotum always single; 

 posterior femur and tibia black, except for a small yellow basal region; 

 apical half of posterior basitarsus somewhat expanded, its basal half yellow, 



apical half black ; pedisulcus very poorly marked yepocapense Dalmat 



White-pruinose longitudinal bands similar to those on yepocapense, the black 

 line separating them being extremely narrow; a few scalelike hairs on 

 mesonotum, often in groups of 2-3 ; on posterior leg the femur is yellow 

 except for apical black ring; posterior tibia is yellow with dark rings near 

 base and at apex ; posterior basitarsus with sides parallel to each other, all 

 yellow except for somewhat darkened area at apex ; pedisulcus well marked. 



ardcni Dalmat 



4. Base color of mesonotum velvety black, the two white-pruinose longitudinal 



stripes expanded anteriorly mathesoni Vargas 



Base color reddish or yellowish brown, the white-pruinose stripes not expanded 

 anteriorly 5 



5. Mesonotum light yellowish brown with longitudinal pruinose stripes curved 



to form a lyre-shaped pattern rubicunduhim Knab 



Mesonotum light yellowish brown with longitudinal pruinose stripes parallel 

 to each other acatenangoensis Dalmat 



6. Basitarsus of posterior leg much expanded on its apical half ; scalelike hairs in 



groups on anterior half of mesonotum 7 



Basitarsus of posterior leg parallel-sided ; scalelike hairs usually single ; when 

 in groups, these are found onlj' on anterior margin of mesonotum 8 



7. Mesonotum shiny black, its scalelike hairs pale golden yellow, narrow; calci- 



pala of hind basitarsus short, not reaching pedisulcus ; pedisulcus poorly 



formed, near base of second tarsal segment mexicanum Bellardi 



Mesonotum velvety black, its scalelike hairs bronze-colored, long and broad; 

 calcipala of hind basitarsus reaching pedisulcus which is well formed one- 

 third the distance from the base of the second segment smarti Vargas 



8. Mesonotum light orange brown, its scalelike hairs in groups on anterior mar- 



gin, single elsewhere ; prescutellar region and scutellum with long black 



hairs ; average total length, 4.0 mm earlei Vargas, Martinez, and Diaz 



Mesonotum dark reddish brown, its scalelike hairs single on all regions ; pre- 

 scutellar region without long black hairs; long hairs on scutellum tan; aver- 

 age total length, 2.8 mm pulverulentum Knab 



SPECIES OF THE SUBGENUS HEARLEA, BASED ON EXTERNAL 

 CHARACTERS OF THE MALES 



I. Band of white pruinosity around entire periphery of mesonotum without inter- 

 ruption 5 



