214 



INSECTS AFFECTING THE ORANGE. 



Recently Professor Riley lias given a more detailed and exact account of the man- 

 ner by which the act of coition takes place. A portion of his article which was 



published in the Scientific American Supple- 

 ment of April 3, 1878, and republished in the 

 Proceedings of the Biological Society of Wash- 

 ington, Vol. ii, 1882-4, p. 81, is here reproduced: 

 " We have seen that, by means of the partial 

 elongation of her puparinm and her partial ex- 

 traction therefrom, the female is able to reach 

 with her head to the extreme lower end of her 

 follicle, causing, in doing so, the narrow elastic 

 portion of the follicle to bulge, and the orifice 

 to open more or less, as it repeatedly did while 

 the larva was yet feeding, whenever the excre- 

 ment had to be expelled. Fig. 94, a, shows a fol- 

 licle cut open so as to exhibit the elongated pu- 

 parinm, and the female extended from it as she 

 awaits the male ; h rej)resents this degraded fe- 

 male more in detail. A cursory examination of 

 the male shows the genital ai-mature, which is 

 always exposed, to consist of (1) a brown, horny, 

 bilobed piece, broadening about the midcfle, 

 narrowiug to and notched at tip, concave, and 

 furnished with a tuft of dark hairs at tip inside; 

 (2) a rigid brown sheath, upon which play (3) 

 the genital hooks or clasps, which are also con- 

 cave inside, strongly bifid at tip, the inner finger furnished with hairs, the outer 



produced to an obtuse angle near tip, and 



generally unarmed (Fig. 95, e). In re- 

 pose, this armature appears as in Fig. 95, 

 c, from beneath, and as at d, from above, 

 and is well adapted to prying into the 

 opening of the follicle. The male abdo- 

 men is telescopically extensile, while the 

 tip easily bends or curves in any direc- 

 tion, but most naturally beneath, as at 

 h, where it is represented enlarged about 

 six times, and with all the genital parts 

 expanded ; k, the fixed outer sheath ; /, 

 the clasps ; g, a jiale membranous sheath 

 upon which the pra'putium (It) plays, as 

 on the fiuger of a glove; i, the lleshy elas- 

 tic penis, armed with retoi'se hairs, and 

 capable of extending to nearly one-fourth 

 of an inch ; j, showing the end still more 

 fully enlarged. With this exposition of 

 details, not easily observed or generally 

 understood, the act of fecuudatnon is no 

 longer a mystery." « 



Fig. 94.— Thyridopteryx ephf.mer.e- 

 FORMis: «, Follicle cut open to show the 

 manner iu which the female works from 

 her puparinm and reaches the end of the 

 bag, natural size; b, female extracted from 

 her case, enlarged. (After Kiley.) 



Fig. 95.— ThYRIDOPTKRYX EPUEMERyBFORMIS : 



6, The end of male abdomen from the side, show- 

 ing genitalia extended ; c, genitalia in repose, ven- 

 tral view; d, do., dorsal view ; e, tip of bitid clasp; 

 i, tip of penis; all enlarged. (After Riley.) 



