320 Report of the Department of Entomology of the 



it exists on other plants. Of those specially mentioned it propagates 

 in largest numbers on wild grape and to a much less extent on sumach. 

 Both are common and widely-distributed weeds. In spite of the 

 conflicting nature of the above evidence as to the influence of clean 

 culture upon the multiplication and spread of the insect, it would 

 seem a good practice on the part of the grower to destroy both the 

 wild grape and sumach even though this now appears as an extreme 

 precautionary measure. 



METHODS OF CONTROL. 



SPRAYING. 



As injury occurs within a short period after fruit has set the orchard- 

 ist should examine his trees carefully, commencing with the drop- 

 ping of the petals, to note conditions with respect to the nymphs. 

 If they appear to be numerous he should resort to spraying to protect 

 the crop. Taking one season with another, an application just after 

 the blossoming period should afford adequate protection. Treatment 

 should not be delayed until injuries commence to show on the young 

 fruits. In the Station's spraying tests, tobacco extract (40 per ct. 

 nicotine (Black Leaf 40), using three-fourths of a pint of the extract 

 to one hundred gallons of water to which are added three pounds of 

 soap) has given the most satisfactory results of the various mixtures 

 which have been tried. In applying the spray the trees should be 

 drenched, special pains being taken to wet both surfaces of the 

 leaves. Some growers have combined the nicotine extract with 

 dilute lime-sulphur containing arsenate of lead as applied for codling 

 moth with equally satisfactory results on both insects and foliage 

 and by this means avoided the necessity of an extra spraying. But 

 as there is danger of burning pear foliage by drenching the trees with 

 lime-sulphur, we would advise, as a general recommendation, a 

 special treatment with nicotine and soap to combat this pest. 



DESTRUCTION OF UNCULTIVATED HOST-PLANTS. 



The fact that the insect breeds most abundantly on wild grapes 

 and to a certain extent on sumach suggests the desirability of des- 

 troying these plants when they exist in the immediate vicinity of a 

 pear orchard. As previously stated, the value of this operation is 

 not known; but until there is more knowledge of the breeding habits 



