~13- 
With 8 each at 25, 50, and 75 feet distances from the center, and 16 stakes 
at 100 feet from the center. At 8 of these points, cards containing fresh 
bagworm (Thyridopteryx ephemeraeformis Haw.) eges were placed on these stakes, 
at a height of 5-1/2 feet, in addition to the cards placed at a height of 
1-1/2 feet on all stakes. Bach card was protected from the sun by a small 
Shingle, Six sets of cards were used during the period of 9 days. The cen 
ter of the check stakes was 1,200 feet west of the point where the releases 
were made. Approximately 40,000 Trichogramma were released on April 26, and 
another 40,000 on April 27. 
No parasitization was obtained on any of the cards of ‘the 6 sets 
placed on the check stakes, or from the first set of cards, which were ex- 
posed from April 26 to 27. The second set, exposed from April 27 to 28, 
' obtained parasitization on 7 different cards, at 25 feet southeast, at 50 
fect southeast, south (low), north (high), north (low), and at 100 feet 
east (low), and east (high). On April 26 wind was first from the south- 
east and later fairly strong from directly southe On April 27 there was a 
slight. breeze from the southwest. On April 28 there was a fair breeze from 
the north. The third set of cards, exposed from April 28 to 40, obtained 
‘parasites at 25 feet southeast and at 50 feet south (high). The fourth set 
of cards, exposed from April 40 to May l, obtained parasitization at 25 feet 
south onlye The fifth set of cards, exposed from May 1 till May 2 (2 p.me), 
obtained parasitization only at 50 feet south (high). large number of 
Trichogramma were still on the center stake on May 1. The sixth set of cards, 
exposed from May2(2 peme) till May 4 (noon), obtained parasitization on 5 
ecards, all at 50 feet east (high), southeast, south (high), south (low), and 
north (low). It wil be noted that parssitization was obtained as far as 
100 feet from the source of origin within 48 hours after the first release of 
Trichogramma, which compares very closely with the results of last year 2 
which parasitization was obtained at 25, 50, and 75 feet within the first 24 
hours after releases 
FOREST INSECTS 
Mortality of Douglas fir beetles—-W. D. Bedard, of the Coeur d'Alene, 
Idaho, field laboratory, reports that while studying the Douglas fir beetle 
{Dendroctonus pseudotsugae Hopke) in northeastern Washington, certain trees 
were noted in which the entire brood of new adult beetles was dead. These 
beetles had not yet passed the winter and, as other trees close by contained 
living brood, this mortality could not be attrituted to extreme high or low 
temperaturese J. C. Evenden,Coeur d'Alene, has also noted this occurence 
in northwestern Wyoming and northern Montanae It is possible that ‘this more 
tality is due to an unknown disease which is sufficiently prevalent to be, 
worthy of additional study. 
Experimental control of the Douglas fir beetle.--Mr. Evenden reports 
that experimental control measures wsre instituted in May against an outbreak 
of the Douglas fir beetle in the Shoshone National Forest, Wyoming, the- ob= 
jective being the preservation of parasites. © Formerly, control operations 
against this insect have been conducted in the fall of the year, as it is 
practically impossible to complete a project in the spring prior to the 
