48 



TIIH BHOWN-TAIL MOTH. 



Seven feiiuile moths which hud not dei)ositcd their cgi>-s 

 were killed iind caicfully dissected. They were found to 

 contain c-os us follows: 844, 300, 217, 28(>, 257, 145, 

 20!), — a total of 1,7.")^, or un average of 251.1 per moth. 



Distribution. 

 The princi})al distribution of the brown-tail moth takes 

 place at the linif when the female moths are on the wing. 

 These insects lly fi-ccly, and have a hal>it of soaring upward 

 above the tree tops and buildings. AVhen the moths in their 

 nocturnal flights have thus risen in the air, the}' are often 

 drifted li\ Ihc wind over long distances. An excellent illus- 

 tration of (he distribution of Hying moths b}^ air currents 

 was given by the high wind prevailing July 12-14, 1897, — 

 a time when the llvini; season of Ihe brown-tail moth was at 

 its height in Somerville and Cambridge. A few weeks pre- 

 vious the caterpillars hud swarmed in nuiltitudcs in these 

 cities, and ifi due tim(> the white-winged moths emerged in 

 myriads. So plentiful were they at this time that arc lights 



