Explanation of Plate T. 



Fig. 1. — The apple-tree bark-louse, Mytilaspis pomorum (Bouche), on apple 



bark. (After Comstock.) 



Fig. 2. — The scurfy bark-louse, CMonaspis furfurus (Fitch): a, the female scales, 

 and b, the male scales, in natural size on twigs; c, the female scale, 

 enlarged; d, the male scale, enlarged. (From the Division of Ento- 

 mology, U. S. Dept. Agr. at Washington.) 



Fig. 3. — The scurfy bark -louse: [a], the male; c, the young larva; /, the male 

 pupa; g, the female, from beneath — all enlarged; b, d, e, 7i, structural 

 details of legs and antenna, in greater enlargement. (From the Divis- 

 ion of Entomology, Washington, D. CO 



