391 



begun to fade, but if they die between October and December the 

 brood will remain until March or April. 



When locating and marking infested trees for felling or treatment, 

 only those with fading foliage or the first stage of the yellowish-red 

 tops need be considered, and before cutting trees it should be 

 remembered that a freshly attacked tree is indicated by pitch tubes 

 on the trunk or reddish boring dust around the base. The lower 

 bark of a tree killed by the beetle ma}/ be living. The tops change 

 from pale green to greenish-brown during the pupal stage and to a 

 reddish hue when the adults emerge, which, in warm months, is 30 

 to 40 days after attack. Trees attacked in November and December 

 will fade either before the spring or in February to April. 



The following details in the methods of control are essential if 

 serious mistakes and ultimate failure are to be avoided. Infested bark 

 from standing or felled trees should be removed and burnt. Infested 

 portions of trunks should be placed in water. The wood of infested 

 trees can be used for fuel or lumber before the beetles emerge. If the 

 larger infested trees are destroyed, neither the tops nor branches need 

 be burnt, or young saplings removed. Dead trees and the lower 

 bark of trunks need not be treated if the beetles have emerged. It is 

 dangerous to cut pine trees in the summer if beetles are killing trees 

 in the neighbourhood. Remedial measures should be carried out 

 between November and March, though in northern localities they may 

 be extended to May. 



Patterson (J. E.). LiJe-history of Recurvaria niiUeri, the Lodge-pole 

 Pine Needle-miner, in the Yosemite National Park, California. — 



Jl. Agric. Res., Washington, D.C., xxi, no. 3, 2nd May 1921, 

 pp. 127-142, 4 figs., 2 plates, 4 tables. 



Investigations are recorded that were carried out in the Yosemite 

 National Park, California, during the summers of 1917, 1918 and 1919, 

 on the serious epidemic of Recurvaria milleri, Busck (lodge-pole pine 

 needle-miner), infesting Pinus nmrrayana. Other investigations under- 

 taken before 1917 are briefl}' reviewed. 



When the moth is prevalent, defoliation becomes marked, followed 

 in later years by the death of the crowns and ends of the branches 

 and the stunting of the growth of the trees. Trees on rocky, exposed 

 sites, under unfavourable soil and moisture conditions, suffer more 

 severely than those in meadows with abundant soil and moisture. 



The length of the life-cycle is 25 months. Flight occurs every 

 alternate year, and in the other years the brood passes the larval 

 stage in the needles of the current year's growth. The eggs are 

 deposited on and under the needle-sheaths and occasionally on the 

 terminal shoots. The larvae hatch in August and September. They 

 feed on the needles b^^ boring in near the outer ends, working towards 

 the bases. This habit accounts for the comparatively prolonged life 

 of the attacked needles. In infested areas, over 7,000 ft., winter 

 commences in October, and insect activity ceases till spring. The 

 winter of the first season is passed in the needles of the current year's 

 growth. In the following August and September the larvae can be 

 seen migrating to new needles, and in October they pass the second 

 winter dormant in the first attacked needles of the second season's 

 growth. In the second spring they again become active and complete 

 the mining of the needles, enter fresh ones of the same growth and 

 prepare to pupate. During its life of 23 months a larva mines three 



