AKT. 21. XOETH AMEPJCAX 6AA\"FLY LAEYAE MIDDLETOX. 19 



Color. — Head: Brownish black; the epistoma, labriim, maxillae, 

 and labium yellow to yellowish brown: antennal and mandibulai 

 membranes pale. Thorax : Prothorax pale orange yellow, excepting 

 the brownish neck plates, laterodorsal spot on D, prehypopleurite 

 which is yellowish, posthypopleiirite which is grayish and the leg 

 joints which are blackish: mesothorax. pale green, with middorsal 

 and laterodorsal brownish spots on A, laterodorsal on B, middorsal 

 and laterodorsal on D, imder B and C on the alar area and on pre- 

 epipleurite. postepipleurite. and posthyiDopleurite : a transverse band 

 on C: prehypopleurite and leg joints with blackish heavy chitin; 

 metathorax, similar. Abdomen: Urite 1 pale greenish yellow with 

 middorsal and laterodorsal brownish spots on A, B. C. and D, supra- 

 alar on B. C and the alar area, alar on the alar area, epipleural on 

 preepipleurite and A. pleural on postepipleurite and hypopleural on 

 that portion of the segment corresponding with the hypopleurite of 

 urites 2-T ; urites 2-7. inclusive, the same but with the hypopleural 

 brown spot on the hypopleurite: urite 8, much similar to urite 1; 

 urite 9 almost entirely pale greenish yellow, but with the alar area 

 and epipleurite each brownish : and urite 10 epiproct greenish yeUow 

 with posterior half between the pseudocerci black. 



Prejmpa. — Size: Length 10 mm.. Head: 1.5 mm, high by 1.5 mm. 

 broad. 



Structure. — Similar to the larva. 



Color, — Head: Brownish. Body: Similar to the larva, excepting 

 that the middorsal line is wanting and that the epiproct is gray 

 posteriorly between pseudocerci. 



Cocoon. — 8.5 mm. long by 3.5 mm. broad, capsule-shaped, blackish 

 in color, consisting of single case, thin, but finely woven. Cocoons 

 are generally found in sand or earth, particles of which adhere to 

 them. 



Host. — Salii\ species. 



Parasites. — Didborus inedmfus Cresson (Determined S. A. Rohwer) . 



Bemarhs. — Described from material collected August 21, 1912, at 

 Ballston, Virginia, by William Middleton and recorded under Hopk, 

 U. S., number 11316.^ These larvae cling to and feed on the edge of 

 leaves with their abdomen curled on the under surface. All had be- 

 come prepupae and entered the ground to spin their cocoons by 

 August 31, 1912. Adults emerged in considerable numbers on Sep- 

 tember 9, 1912, and parasites on September 16 and 21, 1912. 



PTERONroEA MEXniCAXA Rohwer. 



P. mciid'icana much similar to P. icinnanue., differing from the lat- 

 ter species in larger size and having the lower seta or tubercle of the 



