SYRPHIDAE OF MAINE. 239 



the skin, characteristic of the larva is largely lost, due to the inflation. 

 The vestiture remains as in the larva, the segmental spines inconspicu- 

 ous, but the exposed parts of the wrinkles of the larva, densely cov- 

 ered with very small, short, sharp, black spines. Sometimes this gives 

 a rather prominent transverse banding of black where the spines are 

 thickest. 



The posterior three segments are (proportionately less inflated than 

 the middle ones. Shape from dorsal aspect ovate with the last seg- 

 ment and its respiratory appendage projecting; very slightly broadest in 

 front of the middle, nicely rounded out in front. From the side 

 (Fig. 32-56) the anterior and dorsal inflation is evident; the puparium 

 is not strongly elevated posteriorly, being convexly depressed gradu- 

 ally from about the middle. From in front the puparium appears nearly 

 circular in outline, very slightly flattened ventrally. 



Color of the puparium, empty : pale brown, transparent ; with pupa 

 enclosed : variable, darker brown, strongly tinted with salmon. A day 

 or two before emergence the prominent colors of the adult become 

 plainly visible. 



Adult. (Fig. ^2-44). Description after Wiedemann (61) and Osten 

 Sacken (39, p. 145). 



c?. ?. Length 8 to 10 mm. Female. Face yellow, in certain positions 

 with a pearly luster, with a brown stripe in the middle, which begins at 

 •the oral margin but does not reach the antennse; the latter brownish- 

 black, reddish on the underside of the third joint. Cheeks blackish, 

 but separated from the mouth by a narrozv yellow border, which on 

 the underside of the mouth completely cuts off connection between the 

 black color on both sides. Front brownish bronze color, powdered with 

 yellow on each side. Immediately above each antenna there is a 

 brownish spot sometimes continued above into an indefinite black stripe , 

 vertex metallic bronze or black, eyes bare. Thorax metallic greenish 

 black, unstriped; with scattered luteous pile; on the sides, in front of 

 the base of the wing, yellowish ; elsewhere metallic green ; scutellum 

 metallic yellow, with a bluish reflection and sparse yellow pile. First 

 abdominal segment metallic blue ; the rest of the abdomen black with 

 bright yellow cross-bands. The first abdominal cross-band is not 

 interrupted but co-arctate in the middle ; its ends do not touch the 

 margin of the abdomen, but are separated from it by a marrow black 

 border ; sometimes a brownish mark in the middle of this band gives 

 it the appearance of being sub-interrupted. The second cross-band is 

 nearly as broad as the black cross-band between it and the next yellow 

 band; it is usually perfectly straight (in some specimens the' hind mar- 

 gin is gently sinuate) ; its ends do not touch the lateral margin of the 

 abdomen; they are cut obliquely, forming a sharp angle anteriorly, and 

 a rounded one posteriorly; the former almost touches the margin of 

 the abdomen. The third band is similar to the second, only its hind 

 margin is more perceptibly arcuated. The posterior margin of the 

 fourth segment has as usual, a narrow yellow border ; the fifth likewise, 



