maine aphids of the rose family. 279 



Aphid Control. 



On account of their small size aphids, or plant lice as they 

 are commonly known, are to a great extent unnoticed ; but 

 when conditions are favorable to their increase there are many 

 species of these little creatures that are capable of serious dam- 

 age to the vegetation which they frequent and staple crops 

 often suffer severely. 



These insects occur in winged and wingless forms. Both 

 forms feed by means of a jointed beak which they push into 

 the tissues of the plant in order to suck up the sap which 

 forms their food. Since aphids do not feed on the exposed 

 portion of the leaf, stomach poisons like arsenate of lead are 

 not effective as they are valuable only where caterpillars, or 

 other insects which actually eat up the leaf substance, are con- 

 cerned. We need, instead, a contact poison which kills the 

 aphid from the outside of its body since we can hardly poison 

 the sap which it sips. 



Tobacco sprays will kill these soft-bodied insects and as we 

 know of no injury to the vegetation from their proper use we 

 recommend them for most cases where it is possible to spray at 

 all. 



Species inhabiting the trunk or large branches can be de- 

 stroyed in great numbers by using a brush dipped in any of the 

 spray solutions ordinarily used for aphids. 



Tips of branches bearing leaves which have been curled by 

 aphids can be dipped into a pail of tobacco decoction long 

 enough for the solution to penetrate. Such a method as this 

 is of course only applicable for a few treasured plants or small 

 trees. 



For many plants underspraying is a necessity, and for this 

 purpose a sprayer should be fitted with an upturned elbow and 

 a nozzle of the Vermorel type so that the under sides of the 

 leaves can be reached. 



In recent years tobacco extracts have rapidly taken the place 

 of other sprays for aphids, and well informed apple growers 

 are using them almost to the exclusion of other insecticides. It 

 should be remembered that this is a contact insecticide and kills 

 only the insects actually touched. It is, therefore, necessary tO' 

 be very thorough in the spraying. 



