mo 
are doomed, the seriousness of the situation rests ‘upon the possibil- 
ity that the insects may transfer their attacks to white pine after 
Gepleting the lodgepole sine stands. As these tree Species are 
equally acceptable hosts of this insect, and as white vine in associ- 
ation with lodsepole is already being attacked on the Clearwater, 
there is but small hope that such an occurrence will not take place. 
There are large bodies of valuable western white »ine on the Clear- 
water and St. Joe National Forests which at this time are seriously 
threatened by this devastating epidemic of the mountain pine beetle.! 
Piigets of forest inesects!-—T.) Tu Te srrell, Coeur d'Alene, re- 
ports on a nuvei method for studying the flight habits of forest in- 
sects, and submits interesting information obtained by this method. 
It consisted of dttaching'a huzc. insect net to the kite wire of large 
Weather Bureau box kites. The kites were flown over open plains 25 
miles up wind from the nearest timber. There was timber, however, 
14 miles to the northwest and'10 miles tothe east. Eight success- 
ful flights were made, during which the wind varied from southwest 
to west. Although a number of other insects were collected, only 
two bark Deetles were obtained: One, Ips oregoni Eichh., was taken 
from the trap after a flight of 7 hours, during which the kite flew 
| from 1,500 to. 5,000 feet above the ground, and another was taken 
| after a flight of 84 hours. 

Life history of Oregon engraver.--The study of the biology of 
i ips oregoni and associated insects started in April 1931 and termin- 
ated at the close, of the 1933 field seeson. During the first. season 
(April to November), with air temperatures considerably above normal 
and precipitation below average, five complete generations of this 
bark beetle developed in 179 days. In 1982 and 1933 air temperatures 
and precipitation a pproxinated those of an average season and there 
were only four compiete generations of lps oregzoni, which deveoons 
in 184 and 180 days, respectively. From phe results of the 3 years! 
study, air temperatures and moisture are considered to be Ai dominat-— 
ing factors in the develdyment of the Oregon engraver beetle. 


es 
Infestations of western nine beetle influenced by last winter's 
ae ee: 
temperatures.--J. A. Beal, of the Portland, Oreg., field laboratory, 
has just conpleted a report on the effact of low winter temperatures 
on emergence and subdsequent infestation of the western pine: beetle 
(Dendrox -ostonus brevicomis Lec.) in eastern Oregon. A normal emergence 
of 112 beetles per square fost, based'on actual count of emergence 
holes, was found to occur following mild-winters. . Emergence follow- 
ing the abnormally cold winter of 1932-33 ranged from 3 to 29 per 
square foot and was far below that of normal years. Reductions in 
emergence ranged from 74 to oe vercent, depending on the degree of 
cold reached in the area. 
