The Plum. 



81 



sible to avoid removing the delicate bloom that gives an 

 appearance of freshness. 



Plums do not often ripen uniformly enough to permit 

 all to be picked from the tree at one i)icking, and the fruit 

 generally becomes too ripe for marketing if allowed to drop. 

 It is usually necessary to pick over the trees two or more 

 times, the color of the fruit indicating which ones are to 

 be picked. 



98. Parasitic enemies. The chief parasitic enemies of 

 the plum are the plum curculio, plum gouger and aphidae 

 (53) among insects, and the "fruit rot," black knot, 

 and " plum pockets " or " bladder plums " among fungi. 

 These are treated in order. 



99. The plum curculio {Conotmchelus nenuphar) (Fig. 

 27 c.) is the chief insect enemy of the plum and cherry. It 



is native to America and for- 

 merly bred in the wild plums. 

 On the introduction of the 

 European plum, it attacked 

 this fruit so vigorously, until 

 preventive measures were dis- 

 ^^^^ I isSHS'^^ covered, as to threaten its ex- 

 jgfljl^^^ vIl^iF termination from culture. 

 ^^J^^CT n?^^ The perfect insect is a 



rough, grayish or blackish 



Fig. 27. Showing plum curculio, and jjeetle, about OUe-fiftll of an 



stung fruit; o. larva; 6, chiysalis; ^ j^ ^^^ The females begin 

 c, beetle; d, stung plum, showing =_ _ ° 



crescent^shaped mark. Natural size to lay their eggS in the green 



indicated by short Uaes. (After Saun- £^,^j-^. g^^^ ^^i^^^. ^\^q petals fall. 



^^^^ The length of the egg-laying 



period is from two to five weeks, and depends much upon 

 the weather, it being prolonged in cold and wet springs. 



