EGG PARASITES OF THE GIPSY MOTH. 



173 



The 90,000 parasitized eggs were divided into five lots and placed in 

 the field at the proper time in localities where an abundance of eggs 

 was certain. 



The parasites hatched in due course and were found attacking the 

 egg masses in a businesslike manner that was quite encouraging, 

 but only within a very short distance of the center of the colony. 

 The species thus spreads slowly. 



°w.°\ ° 



Fig. 16.— Diagram showing two years' dispersion of Anastatus bifasciatus from colony center. Each 

 concentric circle represents a distance of 50 feet from the smaller or larger circle next it. A indicates 

 parasitism of gipsy-moth egg-masses by Anastatus bifasciatus and O indicates absence of parasitism 

 by Anastatus. The figures give percentages of parasitism. (Original.) 



The accompanying diagram (fig. 16), which has been prepared by 

 Mr. Wooldridge largely from the results of his own work, together 

 with Table VIII, will serve as well as words to tell the story of the 

 dispersion of this parasite in one of the 1909 colonies, and results of 

 similar studies in various other colonies are substantially the same. 



