EE ————— 
- 5 = 
conditions not only prefers mustard to turnips but develops faster, be- 
comes larger and more vigorous, is more prolific, and lives longer thar 
when fed on turnips. The aphids reared on mustard were almost twice as 
large as those reared on turnips, and reproduced as well on mustard as 
they did on turnips during January and February." 
Corm treatments for gladiolus thrips in western New York.--C. A. 
Weigel and Floyd F. Smith, of the greenhouse insect investigations, 
Washington, D. C., spent the period August 9 to 12, inclusive, with F. L. 
Gambrell in western New York in a study of the overwintering of the gladio- 
lus thrips (Taeniothrips gladioli M. & S.) out of doors and the effec- 
tiveness of the corm treatments used by the growers. Their deductions 
include the following statements: "Where the calcium cyanide fumigations 
were improperly repeated and there was a variation in the length of the 
immersion period in mercuric chloride solution, the kill of thrips, 
although high, was incomplete. * * * The ineffectiveness of a 24-hour 
treatment in lye solution was demonstrated by one grower. Where no treat— 
ments were applied the great increase in infestation of thrips in a large 
planting in two succeeding seasons was observed. * * * The nonoverwinter- 
ing of the thrips out of doors was definite in a limited number of in- 
stances, including four places where the corm treatments had been com-— 
pletely successful and at one of these places where the corms left in the 
ground were free of thrips. * * * From the observations of the success 
of the several corm treatments as used by the various growers, the treat- 
ment with naphthalene flakes would probably be one of the most reliable 
as to results, simple as to application, and cheap as to cost." 
FOREST INSECTS 
Control measures reduce Douglas fir beetle 50 per cent in Cody Can- 
yon.--James C. Evenden, Coeur d'Alene, Idaho, reports that "To determine 
the results of control measures instituted in the fall of 1931 against 
an outbreak of the Douglas fir beetle in the Douglas fir stands of the 
Cody Canyon, a survey of the infested areas was conducted during early 
August. This infestation occurred in the valuable scenic timber stands 
that have been severely weakened through defoliation by the spruce bud- 
worm, making the task of control a difficult operation. The data secured 
from this survey indicated a reduction in the infestation of over 50 per 
cent * * * This reduction * * * was rather satisfactory, considering 
the difficulties encountered in conducting the project." Mr. Evenden was 
assisted in conducting this survey by T. T. Terrell and J. M. Miller, of 
the Bureau of Entomology, and by C. C. Spencer, of the Forest Service. 
Windfalls increase bark beetles in Northwest.--"A windstorm of unus— 
ual severity in April, 1931, blew down vast quantities of timber through 
the Cascade Mountains in both Washington and Oregon," reports F. P. Keen, 
Portland, Oreg. "The down trees served as a favorable breeding ground 
for many bark beetles, which has resulted in a beetle outbreak in the stand- 
ing timber of many localities. One such outbreak was investigated in 
Klickitat County, Wash., on the Yakima Indian Reservation and adjoining 
