516 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



pupariii. But, for numerous reasons, although the amount received 

 was hirger, the resuUs obtained, owing partly to the condition of the 

 material on receipt and owing to curious seasonal fluctuations and 

 dilferences in the countries of origin and in the infested territory in 

 America, the results have by no means corresponded with the in- 

 creased material. 



During the year 1909 two important parasites of the gipsy moth 

 (Blepharipa and Parasetigena) were imported in large numbers. 

 They were both hibernated successfully and colonized under ideal 

 conditions in the spring of 1910. 



During 1910 determined efforts have been made to secure adequate 

 numbers of several interesting and probably valuable parasites not 

 yet secured in quantities sufficient to provide for satisfactory colonies; 

 but for the most part these attempts seem to have resulted in failure, 

 although the final word can not be said at this time. 



As the work goes on there seem to be almost as many disappoint- 

 ments as successes. For example, no less than 1,000,000 of a Jap- 

 anese parasite of the eggs of the gipsy moth were reared during 

 the summer of 1909 and the winter and spring following, and great 

 hopes were entertained for its success, but from the present point of 

 view it appears to be wholly unable to withstand the rigors of the 

 New England winter, and another egg parasite, a European species, 

 of which several hundred thousand were reared in confinement, does 

 not appear to make an impression upon the numbers of the gipsy 

 moth eggs in America. 



On the other hand, success of the most promising character has 

 been reached with others of the imported species. Calosoma syco- 

 'phanta^ an imported European predatory beetle, was the first of the 

 imported species to be recovered from the field under circumstances 

 indicative of its ability to exist under American conditions. The 

 season of 1910 is the fourth during which its progress has been con- 

 scientiously followed, and during each of these seasons it appears to 

 have combined a steady rate of increase of approximately tenfold 

 with a rate of dispersion in excess of 1 mile a year in every direction 

 from the center of the original colony. A tenfold rate of increase 

 annually means that 100 beetles liberated in 1906 would have increased 

 to 1,000,000 by 1910, and the actual prevalence of the beetle in the field 

 is such as to make this appear a reasonable estimate of the niunbcrs 

 actually existent. They were so abundant in some localities the past 

 year as to affect the gipsy moth materially, although by no means so 

 materially as to meet and overcome the strong reproductive ability 

 of the pest. If, as there is reason to hope, they will continue to in- 

 crease at this slow but steady rate for some years to come, their effect 

 upon the present prevailing abundance of the moth will be apparent 

 to all. 



Another encouraging example is the tachinid fly of the genus 

 Compsilura, which attacks both the gipsy and the brown-tail cater- 

 pillars as an internal ])arasite. This species was first liberated in 

 190G and was first recovered in 1909 under circumstances indicative 

 of its establishment in America. During 1909 it was found distributed 

 over about five towns adjacent to the one in which the first infected 

 colony was liberated. It was everywhere rare during that 5^ear. In 

 1910 it was expected that it would shoAv a marked increase, but the 

 actual outcome was in excess of all expectations. Instead of a ten- 



