A larger snout-beetle than the curculio, the plum gouger[179] (_Anthonomus scutellaris_ LeConte), occasionally does much damage to plums. The work of the gouger may be told from that of the curculio by the absence of the crescent cut about the puncture made for the egg, and from the fact that the larvæ of this pest chiefly infest the stone and those of the other insect the flesh of the plum. The remedies are the same for the two insects though the gouger is more easily destroyed. Among the several borers which are more or less destructive to species of Rosaceae only the peach borer[180] (_Sanninoidea exitiosa_ Say.) may be counted as a troublesome pest of the plum. The larvæ of this insect are frequently to be found in both wild and cultivated plum trees and must be combated in nearly all plum orchards east of the Rocky Mountains. The prevention of the work of the borer is best accomplished by thorough cultivation, the use of coverings of tar and poisonous washes and mounding the trees. Destruction is effectively carried out only by digging out the borer with knife or wire. The lesser peach borer[181] (_Sesia pictipes_ Grote & Robinson) attacks the plum and in New York has been found particularly injurious to the Wickson plums. The flat-headed apple tree borer[182] (_Chrysobothris femorata_ Fabricius) is frequently found in the wood of wild plums and is sometimes a pest of the several cultivated species. It is treated as is the peach borer. The shot-hole borer[183] (_Eccoptogaster rugulosus_ Ratzeburg) a diminutive insect which deposits its eggs in the trunks or large branches of various members of the genus Prunus, may be regarded as an effect rather than a cause of disease, for it seldom injures perfectly healthy plum trees. The peach bark-beetle[184] (_Phlœotribus liminaris_ Harris) is somewhat similar in its work to the shot-hole borer and like it is found for most part only in diseased and decrepit trees. The plum aphis[185] (_Aphis prunifolii_ Fitch) is sometimes very destructive to varieties of the native plums, especially the Americanas, and occasionally injures or even kills the young trees of the Domestica sorts. It is not a formidable foe in New York, and it is the exception when trees must be treated for it, the treatment being any of the contact solutions used against sucking insects. The cherry aphis[186] (_Myzus cerasi_ Linnaeus) and the green peach aphis[187] (_Myzus persicæ_ Sulzer) are much less common than the plum aphis on plum trees, but are sometimes abundant on foliage of this fruit and are combated in the same way as the more common aphis. Gillette enumerates two other aphids as attacking the plum in Colorado—the rusty brown plum louse[188] (_Aphis setariæ_ Thomas) and the mealy plum louse[189] (_Hyalopterus arundinis_ Fabricius).