6 ACADEMY OF NATURAL SCIENCES 



ing some portion of botanical knowledge, tlie fly carefully insinuates 

 lier elongated oviduct between the vagina of the inner leaf and 

 the culm nearest tbe root of tlie plant, where the larva when ex- 

 cluded from the egg will be in immediate contact with the culm, 

 from which alone its nourishment is derived. In this situation, 

 with the body inverted, the head being invariably towards the 

 roots, or if above, towards the first joint, the infant larva passes 

 the winter. The pressure and puncture of the insect in this 

 state of its being, upon the culm, produces a longitudinal groove 

 of sometimes sufl&cient depth to receive almost one-half of the 

 side of its body. When several of them are contiguous on the 

 same plant, the pressure on the body of the larva is un- 

 equal, and an inequality in the form of the body is the conse- 

 quence, as well as the destruction of the plant which is subjected 

 to their attack. The perfect fly appears early in June, lives but 

 a short time, deposits its eggs and dies ; the insect from these 

 eggs complete the history by preparing for the winter brood. 



Order HYMENOPTERA. 

 Genus CERAPHRON Latr. 



Antennae infracted, moniliform, ten or twelve jointed, basal 

 joint long, cylindrical. Abdomen subovate. Inferior wings with- 

 out apparent nerves. Superior wings with a costal nerve, and a 

 single branch, forming an incomplete radial cellule. 



C. DESTRUCTOR. — Black, granulated; abdomen glabrous, 

 polished ; feet, and base of the antennae, whitish. [48] 



In tlie Larva of Cecidomyia destructor. — Head black, opaque, 

 sometimes brassy, granulated over its entire surface; eyes not 

 prominent, rounded in compliance with the curve of the head, 

 and with the stemmata, red-brown ; antennse pale brown, fur- 

 nished with short cinereous hairs, the two basal joints pale yel- 

 lowish ; the terminal ones in the male a little dilated and ap- 

 proximated so as to form an obvious ovate-acute mass. Thorax 

 with the granulse equal to those of the head; black, usually 

 brassy before the line of the base of the wings ; nerve of the 

 wings pale brownish ; feet whitish with black apophysis. Abdo- 

 men ovate-acute, perfectly black, highly polished and furnished 

 with a few short hairs ; the segments of the base are sometimes 

 pale yellowish or testaceous. Length one-tenth of an inch. 



[Vol. I. 



