248 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 1 



Grevillius^ has shown that if nests of the brown-tail moth be placed 

 in a freezing mixture giving a temperature of — 30° C. ( — 22°F.) for 



Map 2 



IfapiZ. Annual rinlnrun: isotherma of Europe. (Copied froir. Plate 2, 

 Bartholemew'B Fhyeical Atlaa, Vol. Ill, by J.W.Vaa Bibber.) 

 Northern boundarieB of the Brown Tail Moth. Oak, Apple, 

 and Pear ae given by Grevilliue (I.e. text). Cocpiled 

 by author. 



a short time, that most of the larvae are killed, but that only with 

 a minimum of — 35°C. ( — 31°F.) were all killed in larger nests of 



iGrevillius, A. Y., Botaiiischen Centnillliljitt, Band 18. Z\v. Abt., Hefte 2 

 (1905), p. 305-313. 



