PLUM INSECTS 25?^ 



References 



Walsh, First Rept. State Ent. 111., pp. 97-104, 1867 (second edition, 



1903). 

 Riley, 3d Rept. State Ent. Mo., pp. 39-42. 1871. 

 Iowa Agr. Exp. Sta. Bull. 9. 1890. 

 Mont. Agr. Exp. Sta. Bull. 62, pp. 211-218. 1905. 



The American Plum Borer 



Euzophera semifuneralis Walker 



While generally distributed throughout the United States 

 and Canada, this insect has only occasionally become of economic 

 importance. In addition to the plum it has been reported as 

 attacking the pear, apple and mountain ash, and the moth has 

 been reared from larvae feeding on the black-knot of plum. 



The parent insect is a small, obscurely colored grayish moth 

 with an expanse of a little less than an inch. They emerge 

 during late May and early June and are rarely seen, being 

 nocturnal in habit. The eggs are unknown, but are probably 

 deposited in cracks or crevices in the bark of the trunk and 

 larger branches. The larvae eat out winding burrows next the 

 sap wood, cause large dead areas in the bark and in some cases 

 completely girdle the tree. Their presence is usually indicated 

 by the frass thrown out of the entrance to the burrow. When 

 full-growai the larva is about one inch in length and varies in 

 color from dusky greenish to pinkish or reddish. In Delaware 

 the evidence points to three generations annually, adults of 

 the later broods appearing during the latter part of July and 

 in September, but Dr. S. A. Forbes considered the species 

 single brooded in Illinois. The larvae of the last brood mature 

 in early November and hibernate in small white silken cocoons 

 under flakes of bark or in the frass thrown out at the opening 

 of the burrow. About May 1 they transform to pupae, and the 

 moths appear about three weeks later. 



