New York Agricultural Experiment Station. 469 



EXPLANATION OF PLATES. 



Plate XIX. Fig. 1, the oyster-shell bark-louse, natural size; 

 2, view of under surface of some of the scales showing eggs, en- 

 larged; 3, photomicrograph of some of the eggs; 4, scurfy bark- 

 louse, natural size; 5, plum lecanium, a, enlarged, &, natural size; 

 6, the oak scale, natural size. 



Plate XX. Fig. 1, the oyster-shell bark-louse; a, adult male; 

 h, foot of same; c, young larva; d, antenna of «ame; e, adult fe- 

 male taken from scale — a, c, e, greatly enlarged, b, d, still more 

 enlarged. 



Fig. 2. The San Jos^ scale, adult female before development 

 of eggs; a, ventral view showing very long sucking seta?; &, anal 

 plate, showing characteristic ornamentation of edge, greatly en- 

 larged. 



(L. O. Howard and C. L. Marlatt, United States Department of 

 Agriculture, Division of Entomology.) 



Plate XXI. The San Jos^ scale. Fig. 1, infested pear [Duchess 

 d'Angouleme]; 2, portion of the pear enlarged, showing scales 

 about four times natural size; 3, infested pear twig, natural size; 

 4, section of the same, enlarged. 



Plate XXII. Small house for fumigating nursery stock. 



Plate XXIII. The woolly louse of the apple. Fig. 1, infested 

 apple twig, natural size; 2, section of the same twig enlarged, 

 showing gall and lice; 3, roots of young apple, showing galls 

 made by the lice; 4, some of the galls, natural size; 5, scar on 

 trunk of young apple tree in which lice have congregated. 



Plate XXIV. Fig. 1, plum root showing work of peach tree borer; 

 2, a, pupa case with chrysalis emerging; 6 and c. male and female 

 moths ; 3, larva, two views. [Fig. 2, natural size ; Fig. 3, slightly 

 enlarged. From photographs by Mr. F. A. Sirrine.] 4, pistol- 

 case-bearers hibernating on apple twig, natural size; 5, plant lice, 

 Hyalopterus pruni, on under surface of plum leaf, enlarged; 6, 

 young apple leaves drawn together by larva of bud moth. 



