MONTANA EXPERIMENT STATION. 255 



INSECTS INJURIOUS TO CHERRIES. 



24, The Cherry Aphis. 

 A dark colored aphis on the under side of the leaves of cherry. 

 Common in western Montana. Occuring throughout the state. 

 Remedy. — Treat as for apple-leaf aphis. 



INSECTS INJURIOUS TO THE PEACH. 



25, The Peach Tree Borer. 



Primarily a peach pest, but attacking also cherry, prunes and 

 plum. Boring in the trunks near the ground, causing characteristic 

 gummy masses to exude on peach trees. The injury is most appar- 

 ent in the spring. 



Remedy. — A difficult pest to control. Keep the trees well fed 

 and in a healthy growing condition. Prof. Slingerland has recom- 

 mended the use of gas-tar smeared on the trunks to prevent the 

 moths from depositing their eggs, and in combination with this the 

 digging out method to destroy such larvae as gain access to the trees. 



26, The Peach^Twig Borer. 



Though not yet found in Montana, it may turn up at any time. 

 Reddish pink caterpillars boring in the young tender twigs of peachy 

 plum and prune in the early spring, later feeding in the fruit near 

 the pit. 



Spray with strong kerosene emulsion in the winter. The oil de- 

 stroys the worms by penetrating into the holes. 



INSECTS INJURIOUS TO PLUMS AND PRUNES. 



27, Plum Gouger. 



Small beetles, about a quarter of an inch in length, of a leaden 

 gray color with a yellowish head and thorax, eating pinholes in 

 growing plums. The larva of grub feeds in the pit, later eating its 

 way out through the pit and flesh of the plum just as the fruit ma- 

 tures. Attacks only American varieties. 



Remedy. — Jar the trees early in the morning or in the evening 

 when the trees are in bloom and the fruit is setting, catching the 

 beetles that drop on a sheet spread underneath. A few beetles are 

 able to do a great damage. Prof. Gillette found that a single female 



