The Peab Tree Psvlla. 255 



f) or claspers are a pair of narrow blunt black prongs arising from 

 out the caudal end of tbe lower plate; these clapers curve slightly 

 laterad before meeting at their tipt? and thus form an o\'al opening 

 betvi^een them ais seen from behind; the penis (Fig. 5, p) is also a 

 paused organ arising as two narrow knobbed rods from near the 

 middle of the trough. Fig. 5, page 241, shows the ari'angenient of 

 the mariving-s on the abdomen, and the relative size and shape of 

 the parts of the genital apparatus of the male when viewed fi-om 

 the side. Fig. 3 represents an adult female of the ;suimner form 

 with the wings at rest. 



Winter fonn of the adult, Psylla pyricola simulans. — This form 

 differs from the summer form only in isize and coloration. It is 

 nearly one-third larger and the predominating color is black, due 

 to the intensely black markings and the general dark reddish 

 brown color of the body. On, the head, the borders of the epicra- 

 niimi, about the base of the antennae, and a spot near each eye 

 are often whitish; about the base of the beak it is black and the 

 cones of the cl,^Tpeus are blackish with sometimeis a whitish tip; 

 the antennae have their brown portions of a little darkei' color 

 and the basal joint is often black. The tergum of the tliorax 

 varies from being only slightly darker in color than the typical 

 snuimer form to nearly all black, there remaining only a narrow 

 whitish caudal border on the praescutum of the mesothorax, th(^ 

 reddish mesal stripe on the scutum of the imesothorax apjiears avs 

 two narrow stripes so distinct is its black center, and the curved 

 whitish teethi of the scutellum of the mesothorox. The coxae and 

 tarsi are often blackish with the remainder of the legs of a darker 

 brown. The front wings do not have the yellowish tinge and are 

 thus more transparent; the veins are always of a dark brown or 

 blaclv color and more or less distinct black shades occur in the 

 cells; in darlv specimens these shades are vei'y distinct; the stigma 

 is slightly lighter than the veins; the tip of the clavus is distinctly 

 black and a blackish spot occupying nearly one-half of the basal 

 cell extends along nearly the entire length of the claval isuture; 

 anjother blackish spot occurs on the claims along the claval suture 

 near its base. 



