422 



45. Basal joint of fore tarsi about 1.5 as long as fore tilnfe 



37. 7iigrovittatus. 



— Basal joint of fore tarsi about 1.10 as long as fore tibiffi. . .38. liarti. 



46. Apices of femora and bases of tibiae conspicuously blackened or 



browned 47 



— Apices of at least mid and hind femora and bases of corresponding 



tibiae yellow 48 



47. Basal 2 segments of abdomen yellow, the others fuscous 



36. aherrans. 



— Abdomen entirely yellowish or greenish 35. pallidus. 



48. Basal joint of fore tarsi about a sixth longer than fore tibiae 



29. viridis. 



— Basal joint of fore tarsi distinctly more than a third longer than 



fore tibiffi 49 



49. Mesonotum with glossy black or blackish brown vittfe; fore tibia 



and tarsi brown 39. viridicollis. 



— Mesonotum with pale yellowish or reddish vittaj 50 



50. Fore legs yellow, apices of joints of tarsi brownish 



33. stigmnterus. 



— Fore legs whitish green, apices of tibia?, of basal 2 joints of tarsi, 



and the apical 3 joints of latter blackened 51 



51. The greater portion of apical half of fore tibiae and the entire ap- 



ical third of basal joint of fore tarsi blackened 32. frequens. 



— Apex of fore tibiee with a narrow black ring ; apical sixth of basal 



joint of fore tarsi blackened 41. ahortivus. 



Subsection 2 



Fore tarsi with basal joint distinctly more 

 than 1.5 as long as fore tihice 



1. Thorax and abdomen black, blackish gray, or brown, abdomen with 



or without pale posterior margins to segments 2 



— Thorax and abdomen green or yellow, the thorax with or without 



reddish or blackish vittae 10 



2. Males 3 



— Females 7 



3. Fore tarsi without long hairs on their posterior surfaces; legs en- 



tirely yellow ; mesonotum shining black 4 



— Fore tarsi with long hairs on their posterior surfaces ; legs brown- 



ish or partly fuscous; mesonotum gray pruinescent 6 



4. Large species, more than 4 mm. in length; abdomen with pale pos- 



terior margins to segments 43. fuscicornis. 



— Small species, 2.5 mm. in length 5 



5. Abdomen entirely black; fore tibise yellow 44. halteralis. 



— Abdomen yellowish on basal 2 segments ; fore tibige blackened 



45. nitidellus. 



