IXSECTS AFFF.CTING PARK AND WOODLAND TREES 1 27 



defoliation during- the orrowing season. This is specially true of arbor vitae 

 and red cedar. It has been recorded on the foilowini^r trees, beside those 

 previously mentioned : apple, pear, plum, cherry, chokecherry, apricot, quince, 

 linden, catalpa, maple, locust, oak, elm, poplar, sycamore, osajj;e orange, 

 willow, spruce, hemU)ck, larch and white pine. 



Distribution in the United States. This species is stated by Dr Riley 

 to occur in the more southern portions of the middle states and in the 

 southern states, though it appears to be absent from the peninsula of Florida. 

 It occurs within these limits from the Atlantic to Te.\as and reaches the less 

 timbered regions west of the Mississippi. Professor Webster has recently 

 shown that this insect has established itself in Ohicj within 25 miles of Lake 

 Erie. 



Natural enemies. This species is subject to attack by several natural 

 enemies. P i m p 1 a inquisitor Say, P. conquisitor Say, and 

 Hemiteles thyridopterigis Riley, are among the more important 

 ichneumon parasites. The last named is more abundant than the two 

 preceding, and unfortunately, it is probably a hyperparasite preying on 

 the beneficial Pimplas. Chalcis ovata Say is a minute, four winged 

 fly which was reared from this species by Dr Lintner. Dibrachys 



