290 



SCHOOL ENTOMOLOGY 



of the scale, for sprays which will kill all the scales usually 

 injure the foliage. 



Another scale insect very common on old apple trees and 

 also on a number of shade and forest trees, particularly 

 maple and poplar, is the Oyster-shell Scale * (3), so called 

 on account of its oyster-shell shape. The mature female 

 scale is about one-eighth inch long, of a dark brown color, 

 shaped as shown in Fig. 207. The 

 male scale is much smaller. This 

 species is not so injurious, but not 

 infrequently stunts or kills young 

 fruit and shade trees. It is essen- 

 tially different from the last species 

 in its life history, as the females lay 

 eggs beneath the old scales, under 

 which the eggs pass the winter. They 

 hatch in late spring or early summer 

 shortly after apple blossoms drop 

 and the subsequent development is 

 much the same, but there is only one 

 generation a season in the North 

 and two in the South. The same 

 sprays may be used against this spe- 

 cies as advised for the San Jose scale, 

 but they should be applied just before 

 the buds burst in the spring. If this 

 has been neglected, spray with kerosene emulsion contain- 

 ing 15 per cent kerosene, or miscible oils diluted 25 to 30 

 times, just as the eggs are hatching. 



Another species fairly common on apple, pear, and other 

 orchard trees, but rarely doing much injury, is the Scurfy 

 Scale, f The female is a dirty-gray color shaped as shown in 

 * Lepidosaphes ulmi Linn. f Chionaspis furfura Fitch. 



FKJ. 208. The scurfy 

 scale (Ckinoaspis fur- 

 fura Fitch). (After 

 Howard, U. S. Dept. 

 Agr.) 



a, females; b, males- 

 natural size. 



