THE WKSTKKN I'l N K-I)KSTK( >V I .N(} 15A KK 1?KKTI-K. 2'i 



ill the livin*; iiiiicr hark, two adults to a i^allcrv. E^^s occurred 

 sin>i;ly in niches on the sides. 



He estimated that as a resuh of the work l)y tiiis insect near Smiths 

 Ferry 'M) per cent of standin<; tindx-i- was dead and ') per cent was 

 dyin^. Tliis was at the worst j)oint of infestation, i)ut scattered dyin«^ 

 tind)er was found all ovei' Boise and Payette hasins. The same con- 

 dition extended into the liitter Root Forest Reserve. 



OBSERVATIONS BY THE WRITER, 1905. 



The investigations hy the writer durin<; the sununer of 11)05, so far 

 as they related to tliis species, were mainly for the ])urpose of deter- 

 niinint; the principal facts in its life history and habits in the vicinity 

 of (Vnterville and Smiths Ferry, Idaho. The residts may he sum- 

 marized as follows: 



LIFE HISTORY AND U A HITS <)1' TIIK IXSECT. 



HIBERNATION. 



Wliile it is probable, as observed by Hopkins at Clrants Pass, 

 Oregon, tliat a few j)arent adults which enter the bark in the fall may 

 |)ass tile winter in that sta<jc, it appears that it is in the younpj to 

 matured larval stages that the insect normally passes the winter, each 

 individual in a sejiarate mine or cell in the outer corky bark of the 

 tree in which it developed the previous summer and fall. The ear- 

 liest observations at Centerville were made on May IS, when larvae, 

 pujKv, and yountj; adidts were found. Some of the larvjc were small, 

 but the n:ajority of them were n;ature and ready to chan*;e to pupa?. 

 The pupa^ and adults had evidently transformed from larvir since the 

 l)e<;inniji<; of activity in the sprin<^. 



The latest date on which larva' of the hibernatint; broods were 

 found was June lo. Fupa' were found as late as July 8, and adults 

 July 7. It is therefore evid(Mit that the majority of the over-winterinj; 

 broods develoj) to the adult sta^'e by about the middle of June, but 

 broods from cir^s deposited late in the fall may not develop until 

 iKMirly the middh* of Au;rust. Adtdts be<;in to emeri^e in the latter 

 part of May and continue to do so throu<;h June and July and into 

 Au<;ust. Thur; tile perio<l of activity of the hil)ernat in;; l)roods at 

 C\>nterville is j)rol)al)ly from tiie lirst warm days in April and May 

 until about the last of July ap|)ro.\imat(dy *.)() days — the majority, 

 however, coming out in June and in early July. 



KIK.ST (iKNKKATlON. 



The first «;eneration at (Vnterville l)e«;ins with tlie first e^^s depos- 

 itc^l, apparently about the last of June, by the adults developed from 

 hilxMnatin*^ larva* and pupa*. The.se e^^s hatch in about I days after 

 deposition. The j)rincipal e^^j-layin^ period for this <;eneration is 

 evidently l)etween the latter part of June and tlie lirst part of Aufjust. 



