ee 
Cor) 
Winter killing of larvae of brown-tail moth.--C. W. Collins of 
the Melrose Highlends, Mass., field laboratory reports that hiber= 
nation webs of Nvzmia phaeorrhoea Don., collected during January in 
Maine, New Hampshire, Vermont, and Massachusetts, were examined at 
he Melrose Highlands laboratory to ascertain what vercentages of 
the: larvae in the webs’ were dead. The results are given below in 
tubuler forn, ‘tovether with records cf low temperatures furnished 
by the Beston, Mass., office of the leather Bureau. The low- 
temperature readings given ere from towns in which webs were col- 
lected or from adjoining towns and indicate the lowest temperatures 
recorded at the weatiier stations before the dates when the webs were 
collected, these lew temperatures occurring from December 28 to 30, 
inclusive. althougn there is usually sume mortality of small brown- 
tail moth caterpillars after they have entered the hibernation webs, 
the Ccath of ail larvae in 10. collections and the high percentage 
of larvae dead in some of the others were undoubtedly due to the 
unusually low temperatures to which the webs were exposed in the 
field. It should, of ceurse, be remembered that the low temperatures 
given are not necessarily: those to which the webs were exposed, but 
they are the nearest aveiluble.. The lowest temverature to which the 
webs were exjosed may have been somewhat below or above that recorded 
st station. In view. of resuits obtained from other points 
it would, for instance, be ex»xcctced that the webs from Portland, Me., 
were actually subjected -to’a temaerature lower than -18°9 F. 
