The Pear Tree Pstlla. 



241 



oviposit until spring. Several of the adults were observed with 

 a lens while in copulation. The operation was of particular 

 interest; for a glance at Figs. 5 and 6 of the 3exu;il characters and 

 abdomen Avill show that the male organs (Fig. 5, a^ f, 1, p, u) 

 are so peculiarly situated as to seemingly render the grasping of 

 the female organ (Fig. 6, a, e, 1, u) no easy matter. It was found, 



Figures. — Abdomen and genital organs of the male, side view; a, anus; f, forceps; 1, lower 

 genital plate; p, penis; u, upper genital plate. 



how(^A'er, that the caudal segments of the abdomen of the male 

 were tlexil>le and enabled the trough or lower male genital plate 

 (Fig. 5, 1) to be curved upward, thus bringing the forceps (Fig. 5, 

 f) in a position to grasp the upper genital plate (Fig. 6, u) of th.e 

 female; tliis allowed the penis (Fig. 5. p) to enter between (at e, 

 Fig. 6) the valves of tlie female organ, and th.e upper male genital 

 plate (Fig. 5, u) to simply lie along the venter of the lower genital 

 plate (Fig. 6, 1) of the female. A further slight side twist of the 

 abdomen brought the male beside or in some cases upon the 

 female; the wings of both remained in a resting position. The 



* Figure 6.— Abdomen and genital of the female, side view; a, anus; e, egg-sheath; 1, lower 



genital plate; u, upper genital plate. 



hair lines beneath Figs. 5 and 6 represent the natural length of the 

 abdomen including the genital organs. Copulation lasts for sev- 

 eral minutes, and one male may copulate with more than one 

 female. 



The number of broods. — The pest may be said to be many 

 brooded, the number varying with the conditions of the season. 



