204 



AGRICULTURE OF MAINE. 



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Fig. 12. Aspidiotus perniciosus; a, young larva and developing San 

 Jose scale, showing sucking beak with setae separated, with 

 enlarged tarsal claw at right; b, dorsal view of same, still more 

 contracted, with the first waxy filaments appearing; c, dorsal 

 and lateral views of same; somewhat contracted, illustrating 

 further developement of wax secretion; d, later stage of same, 

 dorsal and lateral views, showing matting of wax secretions 

 and first form of young scale. All greatly enlarged. (Howard 

 and Marlatt. Bulletin 62, Div. of Entomology, U. S. Dept. of 

 Agri.). 



"After crawling about for a few hours, the young larva settles 

 down and slowly works its long, bristle-like sucking beak through 

 the bark, folds it antennae and legs beneath its body and con- 

 tracts to a nearly circular form. The development of the scale 

 begins even before the larva becomes fixed. The excreticm 

 starts in the form of very minute white fibrous waxy filaments, 

 which spring from all parts of the body and rapidly become 

 more numerous and dense (Fig. 12 b, c). Within two days the 

 insect becomes entirely concealed by the white or pale grayish- 

 yellow shell or scale, which now has a prominent central nipple 

 (Fig. 12 d). In the early history of the scale it maintains its 

 pale whitish or grayish-yellow color, turning gradually darker 

 gray. The male and female scales are exactly sifniliar in size, 

 color and shape until after the first molt, which occurs twelve 

 days after the emergence of the larva. With this molt, however, 



