188 AGRICULTURAL EXPERIMENT STATION. 



DESCRIPTION. 



The perfect insect is a beautiful butterfly with two and a half tc 

 three inches expanse of wing. It may be known b\' the purplish or • 

 reddish brown wings bordered by a yellowish or buff band, within^ 

 which is a row of violet blue spots. Eggs pale yellow and ribbed. 

 A dozen or more are deposited on the stem near the petiole of a^ 

 leaf. 



The larva when matare is about one and three-fourths inches 

 long; black, minuteh' dotted with white and appearing grayish;: 

 back marked by a row of eight bright brick red spots. The body 

 is armed with from four to seven stiff branding spines on each seg- 

 ment except the first, giving the caterpillar a formidable appearance. 

 The larva are social in their habits feeding in groups on the foliage.. 

 Chrysalis dark brown, with large tawny spots around the tubercles^ 

 on the back. 



LIFE HISTORY. 



The butterflies hybernate in some sheltered place and are on the 

 wing in the spring before the snow is gone, and lay their eggs for- 

 the first brood, which in this region hatches in June, and the larva- 

 are mature late in July or early in August, enter the chrysalis state 

 and the butterfly emerges in ten or twelve days. 



This brood soon la3's eggs, which hatch and the larvte mature ;.. 

 enter the pupa state and emerge before fall, producing the hybernat- 

 ing brood, completing the life history. 



REMEDIES. 



We find but few remedies suggested in the writings of entomolo- 

 gists but see no reason why they might not be destroyed b}' Paris- 

 Green on smaller trees and the branches of larger ones within reach 

 of the spraying pump. 



The natural enemies of this insect help to keep it in check. Out of 

 half a dozen chrysalids put away to transform by Mr. Briggs, only 

 two butterflies emerged and from all the others there came numerous- 

 small ichneumon flies. From one of the chrysalids over one hun- 

 dred and fifty came forth. Some of the specimens were sent to Mr. 

 Howard of the Agricultural Department at Washington, and he 

 called them Pteromalus pupasum. We do not know of this species- 

 having been found before parasitic on the larva of this butterfly, 

 though another species Petromalus vanesscp, Han is, with this habit, 

 is recorded. 



