36 N. H. EXPF.RIMKXT STATION [Bulletin 31') 



dicated that with this species the older eggs were more rapidly pen- 

 trated than the younger eggs. (Adams Fund) 



Insect Records During the Year 



The European corn borer was much more abundant in Xew Hamp- 

 shire in 1939 than for several years past, reports W. C. O'Kane. 

 Commercial damage occurred in a numljer of areas in the southern 

 half of the state. Positive evidence of the occurrence of the two- 

 generation strain in the northern part of the state (Conway area) 

 was obtained. The department cooperated with the Federal bureau 

 in making a fall infestation survey of the European corn borer in 

 Carroll. Merrimack, Belknap. Strafford, and Rockingham counties. 



The gypsy moth was noticeably more abundant this year than for 

 several years past, and the department was called upon to investi- 

 gate outbreaks in many parts of the state. 



Additional observations have been made of the distribution and 

 abundance of the European spruce saw-iiy in New Hampshire. Over 

 1,300.000 Mia'oplectron were reared this season and liberated in the 

 areas where the saw-fly is known to be present. Ecological studies 

 have been continued in the Dul)lin area. These studies are intended 

 to yield information on the effect of predators on the hibernating 

 stages of the saw-fly. The experimental plots originally established 

 on Mt. Monadnock were rendered useless as a result of the hurri- 

 cane of 1938, and new plots have been established on Beech Hill, in 

 the town of Dublin. This work is in cooperation with the Federal 

 bureau. (Hatch Fund) 



Forestry 

 White Pine Stands 



K. W. Woodward supervised the work of thinning and mapping 

 reproduction plots of various ages. Data were obtained regarding 

 the rate of growth of stand, the yield that may be expected at dif- 

 ferent ages, the utilization of small materials derived from thiiming, 

 and thf fli)r.-i and fauna ])resent thri inglmut the life of the stand. 



{Hatch Fund) 



Plantation Studies 



Each plantation was ma])i)ed. measured, and examined. The in- 

 formation collected on the rate of growth of planted Scotch pine. 

 Norway spruce, white spruce, white pine. etc.. will be anal}'zed. 

 Plantations set in 1938 showed a 90 per cent survival in the spring of 

 1939, but it is doubtful whether results will be as satisfactory when 

 the 1939 ])lantations are nu'asin-e<l next year. (Hatch Fund) 



Sustained Yield Study in Northern New Hampshire 



The survey was com])leted July 1, 1939. The area of woodland 

 Cf)vered showed a total of 100.343 acres in Vermont and 188,411 acres 

 in New Hampshire. Timber volume was measured in Coos county. 

 N. II,: all species, 1,129,833 cords; in terms of board feet, 264,541,- 

 240; fence ]iosts. cedar 1,858.035, tamarack 947,247; guarrl posts, 

 cedar S?^'?,72?>. tamarack 33r).424 ; poles, cedar 91,021, tamarack .33.048. 



