Mar., 1913.] Life-Histories of Syrphidae V. 83 



the lower posterior part. From above, the outHne is sub-ovoid, 

 broadest in front of the middle, thence narrowing gradually to the 

 posterior third; whence the puparium is strongly and unevenly 

 compressed to the tip of the respiratory appendage. 



Color at first grayish brown, sometimes marked with oblique 

 patches of black; posterior breathing appendage darker. As the 

 pupa approaches metamorphosis the anterior end darkens to deep 

 reddish-brown in the region of the eyes; while on the posterior 

 half, the three principal, yellow abdominal bands of the adult 

 become visible through the transparent wall. 



The segmental spines remain, as in the larva, very inconspic- 

 uous. The posterior breathing appendage also retains its 

 characteristics. 



Of three specimens taken on July 7, one pupated Jiily 11, the 

 other two the following day. The former emerged as adult July 18, 

 the latter two July 20. Hence the duration in the pupal stage 

 was 7 to 8 days. I did not detennine the place of pupation and so 

 cannot say whether, in the field, this stage is passed within the 

 galls or not. Examination of a number of the galls later in the 

 summer failed to reveal any puparia. 



Adult. 



Male:" Length, 11 to 12 mm. Face and cheeks wholly yellow, 

 antennse reddish yellow, the third joint somewhat brownish above, 

 but little longer than wide, the arista black. Frontal triangle with 

 a small black spot in the middle, gray pollinose along the eyes, 

 black pilose in the middle. Dorsum of thorax shining metallic 

 green, with light colored pile; lateral margins distinctly yellowish 

 pollinose. Scutellum wholly yellow. Abdomen black, the anterior 

 half of the black bands sub-opaque, the three principal bands 

 very broad, attaining the lateral margins in nearly their full 

 width; first band interrupted, the spots narrowly separated, with 

 their inner ends rounded ; second and third bands with a narrow 

 but deep emargination in the middle behind ; fifth and sixth seg- 

 ments with a yellow hind margin. The black forms narrower 

 bands than the yellow, and does not quite reach the. margin. 

 Legs yellow, the tip of hind tibiae and their tarsi brownish. Wings 

 hyaline, the stigma ^^ellowish. 



Female: "Front metallic green, yellow below, on the lower 

 half with yellowish pollen. Yellow spots of the second abdominal 

 segment larger, more nearly square, and only narrowly separated." 

 — Williston, Svnop. N. A. Syrphidae, p. 86. 



