INSECTS INFESTING T HE ^ APPLE TREE. 90 



it can be easily seen that their increase surpasses computation. 



This species is spreading rapidly in the vicinity of Sacra- 

 mento. Trees infested emit a very disagreeable smell. Mr. 

 Haywards, writing of this pest from British Columbia, sa3'S : 

 "After night, in passing along the road I can tell an infested, 

 tree." In cases where trees are badly infested they produce a 

 smell similar to that of decayed fish. I have noticed in hand- 

 ling infested branches that this loathsome smell remains on 

 the hands. 



Leaves infested by these plant lice curl or curve backwards 

 until a roll is formed, thus furnishing the insects with shelter 

 from the rays of the sun, or from rains, or dews, and makes it 

 difficult to destroy the insects by spraying the trees. 



During the Summer they are found grouped together on the 

 leaves in all stages of their growth, and of various colors. 

 The mature insects (Fig. 74.) are of a yelloAvish-green, and 

 when half grown pale-yellowish, and when born the color is 

 nearly white. In Autumn the color changes in many cases, 

 either from the change in temperature or change in nourish- 

 ment. 



Remedies. — When the tree is dormant, spray thoroughly 

 with No. 13 ; one pound of the mixture to each gallon of 

 water used. When the leaves begin to expand, if the lice are 

 present, spray thoroughly with No. 64 or No. 65, and rejDeat if 

 necessarv. 



CHAPTER XLVII. 



The Apple Leaf Aphis. (Cal. ) 



( Aph Is malifolia — Fitch. ) 



Order, Hemiptera ; ) ^^ .-, . 



• Sub-order, Hemoptera ; 1 ^^*™^^>'' ^^^™^^''^- 



[Living upon the leaves of the apple tree, a small, blackish 

 plant-louse.] 



This species infests the leaves of the apple tree, and in their 

 habits they are similar to and are often mistaken for the apple 



