REPORT OF THE ENTOMOLOGIST 219 



SESSIONAL PAPER No. 16 



1905. In July, Mr. John Russell took a specimen of the Moth at Digby, Nova 

 Scotia. 



1907. A single winter web was received by the Division from Mr. C. P. Foote, 

 Lakeville, Kings County, Nova Scotia. Immediate investigation revealed the 

 presence of several thousand webs in Annapolis and Kings Counties. 



1909. Winter webs containing living caterpillars were found in shipments of 

 seedling nursery stock imported into Ontario, Quebec and British Columbia, 

 from France, as a result of the inspection of these shipments. 



1910. A single egg mass received in August, from St. Stephen, New Brunswick. 



1911. Winter webs discovered at Pomcroy Ridge, Charlotte County, N.B., being 

 conclusive evidence of the establishment of the insect in New Brunswick. 

 The infestation in Nova Scotia also discovered to be greater. 



The life history and habits of the Brown-tail Moth have been described in pre- 

 vious reports of the Division (1906 and 1909). By the distribution of these reports, 

 by public lectures and communications to the press, the public are becoming acquainted 

 v ith the facts and the nature of the serious results which would follow the firm establish- 

 ment of the pest in Canada. The financial loss alone would be enormous. We have the 

 experience of the New England States in fighting the Gipsy and Brown-tail Moths to 

 indicate the importance and necessity of taking every possible means, no matter what 

 it may cost, to maintain control of, if not to eradicate, this pest while we are able, as I 

 am convinced we are at present. Some idea of the amount which has been expended in 

 the State of Massachusetts alone on the work of preventing the spread of the Gipsy 

 and Brown-tail Moths may be gathered from the following figures. The work was com- 

 menced in 1S90, and continued until 1900, during which period the total expenditure 

 amounted to $1,175,000. In 1900, the work was discontinued at a time when control 

 was being obtained and the spread was being prevented. Owing to this most serious 

 mistake, both of the moths spread rapidly and in 1905, the State was compelled to 

 undertake the work of preventing the spread, but now on a far larger scale as may be 

 judged from the expenditure. The State of Massachusetts has expended from May, 

 1905, to January, 1910, the sum of $5,500,000, and the Federal Government has ex- 

 pended $417,763.84, making the enormous total of $5,917,763.84. This does not include 

 the amounts spent by corporations and individuals in fighting the insect. I am 

 informed by Mr. F. W. Rane, State Forester of Massachusetts that over $1,000,000 is 

 being expended annually in that state in the fight against the Gipsy and Brown-tail 

 Moths. 



EFFECT OF TEMPERATURE ON THE BROWN-TAIL MOTH. 



•Two factors will govern the distribution of the Brown-tail Moth in Canada : the 

 coniferous forests and the minimum temperature. Unlike the Gipsy Moth, the Brown- 

 tail Moth does not feed upon coniferous trees and therefore the presence of these trees 

 in a pure condition will limit the distribution of this species of moth. 



The limiting power of a minimum temperature, however, is an extremely impor- 

 tant one to take into account in considering the possible distribution of the Brown-tail 

 Moth in Canada, where in certain regions an extremely low temperature may be main- 

 tained for some length of time. For this reason, therefore, the experiments of 

 Grevillius* are of very great interest and importance. He carried out with the aid 

 of various freezing mixtures by means of which very low temperatures could be pro- 

 duced, a large series of experiments on the effect of low temperatures on the hibernat- 



* Grevillius, A. Y. ' Zur Kenntnis der Biologie des G'oldafters (Euproctix chn/sori-hrra 

 L. 11M uthI der durch denselben verursachten Beschadiguugea ' Botanische Centralbl. 

 Vol. 38, Abt. II., pp. 222-322, 8 figs. 1905. 



