PEAR GROWING IN CALIFORNIA. 



381 



the little black adult thrips emerge, feeding upon blossom buds and 

 blossoms of the pear. At this time eggs are laid, from which there 

 develops a brood of whitish-colored larvte, which feed upon the leaves 

 and fruit. The principal injury is done by the adults, which frequently 

 are so abundant that the blossom clusters dry up and fail to bring forth 

 any blossom or fj'uit. 



Control. 



Use Formula No. 11. Application must l^e made first for the adults 

 as the blossom buds are opening. Later applications may be necessary 

 for the larvffi. 



Fig. 173. Injury to pear foliage from thrips, Twniothrips pyri. 



PERNICIOUS OR SAN JOSE SCALE (Aspidiotus perniciosus). 



It is rather strange that the first state in the Union where San Jose 

 scale was discovered should be so free from it at this time. The fact 

 remains that this pest is of little consequence in California. Occasion- 

 ally pear trees are attacked, the injury of the pest being recognized by 



les 



