108 CHESIAS OBLIQUARIA. 



the 17th and the 21st of May, and the later between 

 the 16th and the 20th of June ; with this species also, 

 therefore, it appears there is one brood in the year, 

 variable in the period of its flight. 



I now offer descriptions of the full-grown larvae, 

 giving first the points in which they are both alike, 

 and afterwards those in which they differ. 



Both species, then, have the same food-plant, Spar- 

 Hum scoparium, and are alike in form ; when full- 

 grown they are about an inch or a trifle more in 

 length, uniformly cylindrical and slender ; the last 

 two segments tapering a little to the end of the anal 

 flap ; when they are stretched out at full length in 

 repose the head is bent down and the legs drawn up 

 towards it, an attitude which gives rather a swollen 

 look to the anterior extremity ; the ventral and anal 

 prolegs are moderately well developed. 



C. spartiata is generally of a deep full green on the 

 back, sometimes rather yellower-green on the sides ; 

 it has a dorsal line of much darker green between two 

 lines of paler green than the ground colour ; the sub- 

 dorsal broad stripe is as dark as the dorsal line, and is 

 edged above and below with a fine thread of much paler 

 green ; the spiracular region is puffed ; the spiracles 

 are red, faintly outlined with black ; the inflated sub- 

 spiracular stripe is either primrose-yellow or white, 

 melting a little above into the green ; the anal flap is 

 often rather a deeper green than the ground colour ; 

 the ordinary minute tubercular dots are in the usual 

 position, each bearing a short brown bristle; the 

 ventral surface is green with three pale stripes of 

 whitish-green, the central one being the widest. A 

 yellow variety of this larva often occurs, exhibiting 

 more or less distinctly the details above described ; 

 it is generally found feeding on the broom blossoms, 

 to which it assimilates well. 



0. obliquaria is either of a full green or inclining to 

 bluish-green in the ground colour ; the dorsal line of 

 much darker green is edged with a line of very bluish- 



