

PROC. ENT. SOC. WASH., VOL. 24, NO. 5, MAY, 1922 1 15 



the body at right angles to this axis of the host egg. These 

 habits of oviposition furnish a positive means of identification 

 sometimes very convenient. 



The adults of the two species may also be distinguished 

 by certain structural characteristics. Mr. P. R. Myers has 

 kindly outlined the following comparison of outstanding feat- 

 ures: 



P. vernalis P. hiemalis 



Head quadrate; about as wide as Head subquadrate, distinctly 



thorax. wider than thorax. 



Face convex. Face nearly flat. 



Occiput, vertex, and face dis- Occiput transversely rugulose, ver- 



rinctly transversely rugulose. tex and face shining with faint acic- 



ulations running obliquely away 

 from an indistinct median carina. 



Antenna with base of scape black. Antenna with base of scape pale 



yellow. 



Scutellum laterally margined. Scutellum not laterally margined. 



Legs entirely piceous; tarsi fuscous. Legs dark brown to piceous; tarsal 



joints pale brown except apical 

 joint which is tuscous. 



Wings 2*/2 to 3 times as long as Wings about twice the length of 



abdomen. abdomen. 



Ovipositor straight; slightly en- Ovipositor curved and attenuated, 



arged and blunt at apex. 



BIBLIOGRAPHY 



(1) HERRICK, EDWARD C. 



1841. A Brief Preliminary Account of the Hessian Fly and its Parasites, 



Amer. Jour. Sci. Arts. v. 41, no. 1, p. 153-158. 

 ' 1> FITCH, ASA. 



1S47. The Hessian Fly, Its History, Character, Transformation and 

 Habits, 60 p., 1 pi. Albany, N. V. Literature cited p. 43-44. 



(3) . 



1862. Seventh Report on the Noxious and Other Insects ot the State of 

 New York. Hessian Fly. In Trans. N. Y. State Agr. Snc., v. 21 

 (1861), p. 819-830, 1862. Reprint, 1865, p. 133 144. 



(4) PACKARD, A. S. 



1880. The Hessian Fly. U. S. Ent. Comm. Bui. 4, 43 p., 1 fig., 1 fold. map. 



Literature cited p. 20-21 . 

 (5) 



1883. The Hessian Fly Its Ravages, Habits, and the Means of Pre- 

 venting its Increase. In U. S. Dept. Agr. Ent. Comm. Rep. 3, p. 

 198-248, fig. 9, 1 fold. map. Literature cited p. 219-220. 



