846 THE FRUIT INDUSTRY IN NEW YORK STATE 



APHIDS, OR PLANT LICE 



Three species of plant lice occur commonly on apple trees ; 

 namely, the European grain aphis. Aphis avence Fabr., the green 

 apple aphis, Aphis mall Fabr., and the rosy apple aphis, Aphis 

 malifolice Fitch. An abundant infestation by these insects may 

 result in a large crop of small, gnarly " ..phis apples" so familiar 

 to some growers. All three winter as black eggs, and their appear 

 on the trees with the developing leaves. The rosy apple aphis is 

 particularly likely to be injurious in fruiting orchards, while the 

 green aphis frequently persists throughout the summer on young 

 trees. There appears to be a fairly close relation between serious 

 outbreaks of plant lice and cool, unseasonable weather during late 

 spring and early summer. This is also borne out by the fact that 

 aphis injury is more likely to be serious in the vicinity of the 

 Great Lakes than in places remote from the water, where higher 

 temperatures commonly prevail. 



Extended experiments, conducted under the direction of Pro- 

 fessor Parrott of the Geneva Station, have shown that these pests 

 are most easily controlled by early spraying, namely, just 

 after the buds have burst and before the leaves have developed to 

 any extent. A good contact insecticide is all that is necessary, 

 provided the application is timely and thorough. One of the best 

 preparations is a nicotine extract, 40 per cent, used at the rate 

 of three-fourths of a pint to 100 gallons of water to which from 

 six to eight pounds of a cheap soap (preferably whale-oil soap) is 

 added to serve as a spreader. The tobacco extract may be added 

 directly to the lime-sulphur wash when used either as a late 

 dormant spray or in a more dilute fungicidal solution, in which 

 event soap is undesirable. Frequent infestations by aphids would 

 be sufficient justification for delying the spraying for San Jose 

 scale mentioned above and adding the nicotine in an effort to con- 

 trol both insects with one treatment. A serious aphid infestation 

 may justify special applications later in the season. 



CODLING MOTH 



The codling moth, Carpocapsa pomonella Linn., is the parent 

 of the common apple worm, a pest that may infest and thus seri- 

 ously damage from one-fourth to one-half or more of the crop, 

 much depending on local conditions. 



