this has been found a scale begins to form over the back of 

 the insect, and by October it has become fully grown, has 

 laid its eggs behind it under its scale and has died. These 

 eggs pass the winter and hatch the following June. 



From this it is evident that there is but one brood of these 

 insects each year. Farther south there are two broods a 

 year, and it is possible that there may be two in Massachu- 

 setts in some cases, but, if so, it is unusual. 



Fig. 2. — Oyster-shell scale: o, under side of female scale, showing 

 e?gs ; 6, upper side of same, both much enlarged ; c, female 

 scales on a branch, natural size; d, male scale much enlarged; 

 e, male scales on branch, natural size. The fine lines to the 

 right of a, 6 and d show the real length of the scales. (Howard, 

 U. S. Dept. Agr. Yearbook, 1894.) 



Treatment. 



As the eggs of these scales all hatch about the first of 

 June, this fact may be taken advantage of in the treatment. 

 The crawling young are entirely unprotected by any scale, 

 are soft-bodied, and can be killed by spraying with kerosene 

 emulsion or with whaleoil soap, if taken at the right time. 

 The only difficulty is that in order to be destroyed each one 



