348 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



visible segments. P. pubescens was therefore wrongly 

 placed when attributed to the genus Triglyphus by 

 Loew.) 



Key to Species of Pipizella 



1. Face and frons entirely whitish pilose 2 

 Face or frons partly blackish pilose 4 



2. Third joint of antennae four or five times as long as wide; wings 



dark brown australis 



Third joint about four times as long as wide; wings hyaline or 



almost so 3 



3. Scutellum with apical groove; auxiliary vein ending well beyond 



apical cross-vein pulchella 



Scutellum without apical groove; auxiliary vein ending hardly 



beyond apical cross-vein occidentalis 



4. Thorax conspicuously reddish pilose; abdomen with some reddish 



or reddish-yellow pile ; antenna? entirely black (western species). 



rufithoracica 

 Pile not so colored 5 



5. Arista microscopically pilose on basal quarter; abdomen of male 



brassy pubescens 



Arista at most pilose at immediate base; abdomen of male not brassy 6 



6. Arista pilose at immediate base (to end of first section) antennae 



reddish below; moderately robust species; (6.5 to 7 mm.) modesta 

 Arista bare (in all species examined); smaller and more slender, if 



very similar the antenna; are black throughout in the male 7 



7. Wings with a large brown spot in the middle *bellula 

 Wings without median brown cloud 8 



8. Third joint of antennae partly reddish, about four times as long as 



wide pulchella banksi 



Third joint of antennae usually entirely black, about three times 



as long as wide fraudidenta 



1 . Pipizella pubescens (Loew) (Figs. 7, 9, 10, 40) 



Triglyphus pubescens Loew, Century, iv, No. 61, 1863. 



Pipiza pubescens Williston, Synop. N. Am. Syrph., 

 23, 1886. 



Habitat: Wisconsin (Lw.) Ontario! Shining black 

 to brassy; front basitarsi slightly, the hind ones con- 

 siderably, incrassate. 



Length about 5 mm. Male: Face and frons metallic bluish black, moder- 

 ately long white pilose; sides of face and frons to well above the antennae nar- 

 rowly whitish pollinose; eyes blackish pilose, across the middle with a well- 

 marked horizontal bare stripe. Antennae elongate, black, second and third 

 joints testaceous below, third joint over twice as long as broad, the end evenly 

 rounded. Thorax and scutellum shining black, the former with a coppery 

 reflection; pile luteous, on the pleurae white and longer. First segment of 

 abdomen black; remaining segments shining greenish black with a brassy 

 reflection, anterior and posterior margins of segments with ill-defined opaque 

 bands not reaching lateral margins; pile short, white, the posterior margins 

 of second to fourth segments and anterior margins of third and fourth, with 

 rather narrow black pilose bands. Hypopygium with a few white hairs. Legs 



*No description available. 



