162 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



half their width (those on the third segment are from 0.15 to 0.22 mm. 

 apart, those on the fourth 0.23 to 0.27 mm.) "and not quite reaching the 

 lateral margin." The anterior lateral corners of these segments are nar- 

 rowly yellow, the posterior margin of the third narrowly so in the middle 

 and of the fourth more broadly. Fifth segment with an arcuate black 

 band reaching the anterior margin in the middle, leaving the posterior 

 margin, more broadly in the middle, and the anterior corners yellow, which 

 latter make with the yellow of the preceding segment an arcuate yellow 

 band attenuated in the middle. Venter yellow except for small black 

 patches at the posterior corners of the principle segments. Legs rather 

 more yellowish than in Williston's specimens, the anterior and middle 

 pairs being entirely yellow, the hind ones infuscated somewhat on the mid- 

 dle of the femur and from the basal third of the tibia outward. "Wings 

 hyaline, with a slight smoky tinge; stigma yellowish." 



In all my specimens the abdomen reaches its greatest width at the tip 

 of the second segment, which Williston states is characteristic of his spec- 

 imen of felix, but the yellow spots of the abdomen are much too widely 

 and distinctly separated to fit Osten Sacken's description of felix. 



No adults have been taken in the field except the two fe- 

 males mentioned above which were captured about aphid col- 

 onies. However I have an Ohio specimen which agrees with the 

 Maine specimens in detail. 



SYRPHUS ORONOENSIS n. sp. 



Larva (Fig. 10, A). Length about 11 mm., width 2.5 to 3.5 mm., height 

 1.5 to 2.5 mm. In outline the larva may be described as very elongate, sub- 

 triangular; somewhat more flattened than the ordinary aphidophagous lar- 

 va, being sub-triangular in cross-section. The lateral margins are serrated 

 and the posterior end convex rather than truncate. 



Conspicuously colored, the posterior two-thirds or three-fifths of the 

 body being chalky white, except along the margins; the anterior third or 

 two-fifths as well as the entire lateral margins and the terminal segments, 

 bright tan, maroon, or even quite black, depending on the stage of develop- 

 ment of the larva. This sharp contrast of colors gives to the larva an ap- 

 pearance quite suggestive of bird-droppings especially when found* curled 

 about small twigs. 



A more detailed examination of the color and pattern, which appears 

 to vary only in details, shows that the anterior segments of the body vary 

 from dark greenish gray to black as a ground color, with a median narrow 

 stripe of white in segments four, five and six, and more or less extensive 

 mottling with clusters of globular adipose bodies which vary from tan to 

 dark maroon, the lighter colors prevailing on the younger larvae. The 

 darker colors which occupy all except the narrow, mid-dorsal line through- 

 out the first six segments, become restricted to progressively narrower 

 and narrower lateral margins throughout segments 7 to 11, but again 

 occupy the entire dorsum in segment 12. 



