16 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



segment; iirite 9 is similar to urite 1, but has the transverse band 

 terminating at the alar region, and urite 10 is entirely pale yellow. 



Prepupa. — Size : 11 mm. long. Head : 2.25 mm. by 2.25 mm. ; much 

 similar to the larva in structure and color. 



Cocoon. — 12 mm. long by 5 mm. broad: black: single-walled; 

 typical Croesus cocoon. 



Host. — Gastanea dentata (Marshall) Borkhausen. 



Renuirks. — Described from material collected August 7, 1912, at 

 Falls Church, Virginia, by S. A. Eohwer and William Middleton 

 and recorded under Hopk. U. S. number 10154, supplemented by ma- 

 terial collected August 30, 1912, at Vienna, Virginia, by R. A. Cush- 

 man and recorded under Hopk. U. S. number 10154* and September 

 21, 1912, at Blytliedale, Maryland, by C. T. Greene, recorded under 

 Hopk. U. S. number 11323. ' 



The larva of this species is a gregarious edge eater and seems to be 

 rare, since onl}^ 4 or 5 colonies have been collected. The larvae that 

 were collected August 7, 1912, had finished feeding and had entered 

 the ground for pupation by August 17, 1912. Adults emerged in the 

 rearing cage on September 16, 1912. 



Genus PTERONIDEA Rohwer. 



PTERONIDEA AMELANCHIEUIDIS Rohwer. 



Larva. — Stage VI. — 



Strueture.^Head : Nematine in type ; antennae of the cone and disk 

 type which are but slightly jointlike and 4 in number; maxilla with 

 palpifer and 4-jointed palpus, lacinia broad and flattened with 15 

 or so bladelike setae along apical margin and this armature with a 

 large gap near galea (fig. 5) ; labium with palpiger and 2-jointed 

 palpus. Thorax : The tergum with A prothorax and D of prothorax, 

 mesothorax and metathorax bare, A of the mesothorax and meta- 

 thorax and B and C of the prothorax, mesothorax, and metathorax 

 with a few short hairs ; B and D terminating in the alar region with 

 acute angles, due to enlarged, broad, and sparsely haired alar area 

 which is well separated from preepipleurite ; the pleurum with pre- 

 epipleurite, prehypopleurite, posthypopleurite and leg joints 

 sparsely haired; legs with 4 joints and a claw, joint 3 with large pad 

 on inner side at apex. Abdomen : The tergum of urites 1-9. inclu- 

 sive, is composed of A. B, C, and D (B and C are not as distinctly 

 separated as A and B or C and D, and C is inclined to subdivide 

 Qi-2-3^ ; A, B, and C^ with few hairs, D bare and narrow; urite 10 

 composed of epiproct which is sparsely haired and wdthout pseudo- 

 cerci; urites 1-8, inclusive, contain spiracle in a rather w^ell defined 

 spiracular area and urites 9 and 10, without spiracular area and 

 spiracle; urites 1-9, inclusive, with alar area neither well developed 

 nor distinctly bilobed, wanting on urite 10; pleurum; urites 2-7, 



