PEAR GROWING IN CALIFORNIA. 



383 



SHOT-HOLE BORER OR FRUIT-TREE BARK BEETLE 



(Eccoptogaster rugulosus). 



This species is very similar to the lesser shot-hole borer already men- 

 .tioned. It is a larger species, however, with like habits. 



Control. 



Same as for lesser species. 



SPRING CANKERWORM (Paleacrita vernata). 



Cankerworms may be distinguished from other species of moth larvae 

 that feed upon fruit trees by the absence of all but two pair of prolegs. 

 They are green or brown in color. Feeding is confined to the foliage, 

 which may be destroyed entirely in severe cases. 



Control. 

 Use Formula No. 3 or 12, or the two in combination. 







FIG. 175. Young pear tree injured by root aphis, Eriosoma pyricola. 

 PEAR ROOT APHIS (Eriosoma pyricola). 



This very destructive species of plant louse is very similar to the 

 woolly aphis of the apple. Unlike the apple aphis, however, it feeds 

 entirely upon the root system of pear trees. Its attack is confined princi- 

 pally to the very small fibrous roots. In the pear-growing regions north 



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