4 ACADEMY OP NATURAL SCIENCES 



with cinereous, a lunate impression on each side before, an impres- 

 sed band on the middle interrupted on the back ; and an impressed 

 ano-ulated one behind. Lateral spines short, black 3 posterior ones 

 longer, rufous. Wings fasciated with brown near the apex. Feet 

 rufous, thighs, and tibia towards the tips, blackish, anterior thighs 

 thickened. Poisers white. Abdomen black immaculate. 



Length rather more than three-twentieths of an inch. 



Extremely rare ; I found but a single individual in May last 

 seated on a leaf of the Skunk Oabbage, {Pothos foetida) near the 

 Wissahickon Creek a few miles from this city. This insect will 

 be considered as a most interesting addition to the American Fauna. 

 (^Achias Fab.) 



The insects above described I believe to be new, at least they 

 are not noticed in any book to which I have access. 



[Prom Vol. 1, No. 3 : pp. 45—48.] 



Some accoont of the insect known "by the name of Hessian Fly, and of a 

 parasitic insect that feed3 on it. 



Kesid June 24th, 1817. 



Order DIPTERA. 



Genus CECIDOMYIA. 



Genus Ttjnda of Linn6 and Degeer. Chironomus of Fabr. Tri- 



chocera of Lamarck. Cecidomyia of Latr. and Meigen. 



Antennae filiform, joints subequal, globular, hairy. Proboscis 

 salient. Wings incumbent, horizontal. 



C. DESTRUCTOR. — Head and thorax black ; wings black, ful- 

 vous at base ; feet pale, covered with black hair. 



Inhabits the Northern and Middle States. 



Body clothed, with short black hairs ; head black ; antennae 

 shorter than the body, somewhat smaller toward the tip, verti- 

 cillate, joints moniliform, separated by a hyaline filament. Tho- 

 rax gibbous, black, glabrous, and polished. Scutel prominent, 

 color of the thorax rounded behind. Wings ciliate, rounded at 

 tip, blackish, the fulvous color of the base is sometimes ex- 

 tended upon the nerves of the wing, paler and graduUy disap- 

 pearing before the middle j longer than the abdomen. Feet long, 

 slender, [46] thighs fulvous at base, furnished at the tip with 



[Vol. I. 



