
5 
and carried along the logs by spraying on fuel oil from a back pump. 
From one-half to three-quarters of a gallon of oil was sufficient for 
the average-sized tree. A good kill of brood was secured and it was 
found that with certain precautions the method could be used in very 
hazardous areas. In more open areas the infested trees were decked and 
burned. The cost of the method is only slightly more than of the sun-— 
curing method," 
Seasonal history of pine beetles.-—-"Seasonal history records of 
ips confusus Lec. and Dendroctonus brevicomis Lec. were kept during the 
LL Tee eet era ta i 
month by R. L. Furniss near Bass Lake," reports J. M. Miller, Berkeley, 
Calif. "At elevations between 3,000 and 4,000 feet two seasonal gen- 
erations of Ips had been completed by June 30 and the third generation 
was in progress. Emergence from the earliest of the first seasonal 
generations of Dendroctonus brevicomis was occurring by June 25 and at-— 
tacks of the second seasonal generation were in progress. However, 
for the greater part of the infestation above 4,000 feet elevation the 
first generation had not emerged by the end of June." 
, Penetrative oils retard development of pine beetle.--Mr. Miller 
also reports that "Experiments in the use of penetrative oils on bark 
infested by the western pine beetle, as a means of treating infested 
trees during the summer period when burning is impracticable, were con-— 
ducted at the Bass Lake base in cooperation with Mr. Gay of the Stand- 
ard Oil Research Laboratory. Only a few of the oils tried so far have 
shown effectiveness. It was found, however, that some of the lighter 
mineral oils, when applied to the. outer bark on the tree, work through 
the ventilation holes into the egg galleries and eventually reach the 
larvae in the larval mines. The first effect of the oil is not toxic, 
but striking retardation of the brood development was observed. In 
several tests practically all the brood died after remaining in this 
retarded condition for about two and one—half months." 
CEREAL AND FORAGE INSECTS 
Se ee 
conformance with a more economical plan of operation in the corn borer re- 
search work, it was decided to suspend for the present the work of col- 
lection and shipment of corn borer parasites from the Orient. In accor- 
dance with this decision the laboratory formerly operated at Kobe, Japan, 
was closed early in June and C. A. Clark, who was in charge, came to 
America, arriving at Arlington, Mass., on June <3, 
The western spotted cucumber beetle in relation to sweet corn in 
Oregon.——T. R. Chamberlin, Forest Grove, Oreg., reports: "Adults of the 
new generation (those which came from the eggs of overwintering beetles) 
were first found near McMinnville on June 24. They were common in the 
fields on June 27. Issuance this year was approximately 1 week later 
than last year. A field of sweet corn that had been injured by larvae 
of Diabrotica soror Lec. was seen on June ll. It was estimated that 
