PINE SCALE-INSECTS. 



805 



144. Paylla tripuncta Riley. 



A pretty reddish or pale brown species ; spun on leaves April 4, 1883 ; wings with 

 three broad brown stripes ; an oblique stripe in middle of wing. 



Professor Riley states that Psylla tripuncta is ''very common on pine 

 trees from Canada to Florida" (Amer. Ent., fig. 17, p. 62). 



145. Pine-leaf cuermes. 

 Chermes pinifoliw Fitch. 



Order Hemiptera ; family Aphid^. 



Stationary upon the leaves, usually towards their ends, puncturing thera and suck- 

 ing their juices, a very small black fly 0.08 long to the tip of its abdomen, and 0.12 

 to the end of its wings, which are dusky gray, its abdomen dusky red and slightly 

 covered with fine cottony down. (Fitch.) 



" The females of these insects do not extrude their eggs. Clinging 

 closely t© the leaf with their heads towards its base, they die, their 

 distended abdomens appearing like a little bag filled with eggs. The 

 outer skin of the abdomen soon perishes and disappears, leaving the 

 mass of eggs adhering to the side of the leaf, but completely covered 

 over and protected by the closed wings of the dead fly. I have met 

 with the dead females thus adhering to the leaves the first of July, and 

 have noticed the same insects on the leaves in full life and vigor the 

 middle of May." 



The rib vein of the forewings runs straight to the outer margin forward of the tip, 

 and gives off from its middle on the outer side a very oblique branch which runs to 

 the outer margin, its tip producing a slight angular projection of the edge of the 

 wing, and the whole space on the outer side of the rib vein beyond this branch is more 

 opaque than the rest of the wing and of a smoky yellowish color. From its inner side the 

 rib vein sends off three simple oblique 

 veins, the last one of which ends in 

 the extreme tip of the wing. The 

 hind wings have an angular point 

 on their outer side beyond Lhe middle, 

 and a longitudinal rib vein, which, 

 forward of its middle sends off a 

 branch almost transversely inward, 

 its tip curved backward. The an 

 tennjB are short, thread-like, and com- 

 posed of four or five small joints. It 

 will hence be seen that this insect 

 is a true Chermes — the first species of 

 this genus that has been discovered 

 in this country. (Fitch.) 



146. The pine-leaf scale-insect. 

 Mytilaspis pinifoUce (Fitch. ) 



Order Hemiptera ; family Coccid^. 



Fig. 274. — Pine-leaf scale-insect; a, natural size on pine 

 leaf; b, male ; c, d, female scale. After Riley 



Fixed upon the sides of the leaves 

 of young trees, exhausting them of 

 their juices and causing them to turn yellow ; small oblong flattish white scales, with 

 a pale yellow spot upon their pointed end. (Fitch.) 



