98 ANNl'AL ItKPORTS OF hKl'AHTM K NT OF A(.KI( TI/ITKK, H»4<' 
This survey supplements the one made during the spring of L939 
in Argentina, uinguay, and southern Brazil. These studies are 
yielding much information regarding the range and hal it> of the 
pest in its native habitat, from which tentative conclusions regard: 
ing its future spread in the United States, and the extent of its 
attack upon different crops, may be drawn. No natural enemies 
nave yet beejn found. 
PARASITES OF COTTON INSECTS 
Activities on parasites of the pink- bollworm were limited to the 
importation of an additional rearing stock of Micfobracon kirk- 
patricki from Egypt and continued rearing work in Japan to build 
up a stock of Vhelonm peciw/rphorcu Cush. for shipment later 
in the year. 
PARASITES OF FOREST INSECTS 
In continuation of the cooperative activities of the Bureau with 
the Canadian Department of Agriculture upon the spruce sawfly 
in Europe, it was possible to make a survey covering Sweden, Fin- 
land, and Norway during July to September, 193i>. This survey 
supplemented that made in northern Europe during the previous 
year. In Sweden and Finland it was found that parasite attack 
upon the sawfly larvae ranged up to CO percent, and infestations 
sufficient extent to permit of large-scale collecting activities were 
found in these countries. Sample collection- of about 3,000 coco 
were made during the course of the survey and these were forwarded 
to the parasite laboratory of the Canadian Department of Agricul- 
ture for rearing with their own larger collections made in the same 
localities. Approximately 80,000 adult parasites, of 10 European 
species, were received from the Canadian Department of Agricul- 
ture for colonization in infested areas in the United State.-. 
PARASITES OF FRUIT INSECTS 
Importations of Japanese beetle parasites consisted only of 61tS 
adults of the Chosen (Korean) strain of Tiphia poptlftavora for use 
as a rearing stock to provide colonies for later release. 
The principal studies on natural enemies of the oriental fruit 
moth in Japan and Chosen dealt with the determination of the alter- 
nate hosts of several of the more important species. Tnareolata mo- 
lesftic. which increases rapidly during the season of release in the 
United States hut has difficulty in passing the winter in satisfactory 
numbers, was found to have a considerahle numher of alternate ho<t< 
in Japan. Some of these are apparently much moie suitable for 
hibernation than is the fruit moth. No parasites of this pest were 
imported during the year. 
One of the new activities of the Yokohama station is the study 
: nd importation of parasites of Ps< \idococcus com&tocki, a pest of 
Asiatic origin which is becoming a major pest of apple in the 
eastern part of the United State-. In Japan this inject is not an 
important pest and i> apparently controlled by natural enemies. Six 
specie* of parasites have been found, one of which already occurs 
in the United States. Shipments thus far made from Japan total 
approximately 166,000 larvae of 8 undescribed species of AUotropa, 
l species of Afiagyvus^ and l of Leptomastix. 
