170 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



Larva (Fig. 11, C). Length 10 to 11 mm., width at middle 1.75 to 2 

 mm., height about 1 mm. An elongate, slender-bodied, nearly parallel- 

 sided larva more than five times as long as broad, with moderate trans- 

 verse wrinkling and gently, irregularly-serrated margins. The color is a 

 beautiful bright tan; the mid-dorsal blood-vessel forms a continuously 

 black line throughout most of the length and is margined on each side 

 with a broad, whitish stripe of adipose tissue, giving off at the sides irregu- 

 lar, slender, curved tongues of similar color which together form another, 

 indefinite, narrow, irregularly curved and broken stripe of white. A third 

 pair of whitish stripes, slender, broken and irregular, lie close to the lat- 

 eral margins. The integument is finely and evenly papillose but is devoid 

 of integumental vestiture. The segmental spines are light, concolorous and 

 small, O f two segments, the basal one about 0.015 mm. long by 0.022 mm. 

 broad, truncate-cone-shaped, the distal one 0.007 mm. in diameter and 

 about 0.03 mm. long, tapering slightly but blunt at the tip. The anterior 

 larval spiracles (Fig. 11, B) show five minute denticles arranged in a semi- 

 circle. 



The stigmal plates (Fig. 11, H) are almost sessile, the respiratory 

 tubes which bear them being about 0.18 mm. long by about 0.25 mm. in 

 width by about 0.12 mm. in height. The circular plates or buttons are 

 quite distinct and circular, 0.04 mm. in diameter, and each slit-like spiracle 

 about 0.0375 mm. in length by about 0.0075 mm. in width, but its sides lined 

 with a row of separate minute, rounded denticles which increase the ap- 

 parent width to 0.015 mm. There are ten to a dozen such denticles along 

 each side of each spiracle. I find no trace of interspiracular ornamentation 

 except a very small rounded nodule, the surface of the stigmal plate ap- 

 pearing quite smooth except for the spiracles. The end of the respiratory 

 organ is decidedly emarginated between the two stigmal plates and the 

 plates turned outward giving the tubes the appearance of being somewhat 

 divergent at their tips. 



Puparium (Fig. 11, I, J,). Length 5.5 mm., maximum width 1.85 mm., 

 maximum height 1.75 mm. The colors of the larvae are at first carried 

 over into the pupa stage but are gradually transformed to a more uniform 

 reddish brown although the black and white stripes of the mid-dorsum 

 persist for a longer time. The integument becomes fairly smooth, much 

 indurated and glazed. 



The puparium is moderately inflated, globose in front, broadest about 

 the anterior third thence somewhat irregularly and gradually attenuated 

 to the posterior end. In side view (Fig. 11, I) the ventral line is seen to 

 be gently convex, the dorsal line arising nearly perpendicularly from it, 

 but soon rounding away to its maximum height about the anterior third. 

 Thence it descends with a moderate hump over the posterior third to the 

 posterior respiratory organ which is terminal. 



Adult (Fig. 11, D, E, F, G). I quote in full Verrall's origi- 

 nal description i 1 



'British Flies, Vol. VIII, pp. 290-292. 



