Fluke—Syrphidae of Wisconsin. 
233 
12 . 
13. 
14. 
extreme base, thorax shining. 
{ 
15. 
16. 
17. 
18. 
19. 
20 . 
Cross-bands rather broad and undulating, reaching side mar¬ 
gins very narrowly on their upper sides only, thorax 
r nitens 
brightly shining ...j _ _ . , 
1 abbreviatus 
Bands not so undulating and reaching side margins more 
broadly ... male ribesii 
Third joint of antennae at least twice as long as wide; cheeks 
black, face with a median stripe.species no. 3 
Third joint usually less than twice as long as wide, cheeks us¬ 
ually yellow ... 
Bands undulating and reaching the side margins by their 
upper corners only, front and middle femora black at the 
nitens 
abbreviatus 
Bands not so undulating and reaching side margins more 
broadly, thorax with indistinct light grey lines. 
Hind femora of both sexes reddish or yellowish at the base... 
..-. protritus 
Hind femora of male black at the base. . ribesii 
Hind femora black at the base... grossulariae 
Hind femora yellow at the base..... 
Lateral margins of the thorax with yellow stripes in ground 
color, antennae pointed . Tcnabi 
Lateral margins without yellow stripes in ground color, an¬ 
tennae rounded . 
Smaller species, 6 to 8 mm...var. ribesii 
Larger species, 10 to 12 mm.... 
Scutellum yellow-haired, bands broad. xanthostomus 
Scutellum black-haired, bands narrower. protritus 
Antennae reddish or yellowish, seldom blackish, third joint, 
nearly as wide as long, pile of pleurae yellowish, bands 
f nitens 
^ abbreviatus 
of abdomen undulating 
21 . 
22 . 
Antennae blackish or deep brown, at least on the upper side 
of the third joint, which is usually nearly twice as long 
as wide, abdominal bands more straight. 
Abdomen rather narrow with nearly parallel sides in the male; 
smaller species; bands broadly biconvex posteriorly, nar¬ 
row in the female.species no. 2 
Abdomen more oval; larger species; bands more straight. 
Hind femora black at the base, the middle femora on the out¬ 
side with a row of rather heavy black pile with a few 
pale hairs intermixed; antennae somewhat larger. 
.species no. 3 
Hind femora of female yellow at the base, middle femora with 
a row of mostly yellowish pile, very seldom any black hairs, 
present; antennae smaller. americanus 
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18 
19 
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