- 49 - 
1939 
Baird, A. B. (250) 
Biological control of insect pests in Canada with special reference 
to the control of the European spruce sawfly, Gilpinia polytoma 
Htg. Ent. Soc. Ontario Ann. Rpt. 70: 51-56." 
The woolly apple aphid parasite, Aphelinus mali , transferred 
from Belleville, Ont., in 1929, has reduced its host and proved 
of tremendous value to the Okanagan growers. 
Clausen, C. P. (251) 
Some phases of biological control work applicable to sugarcane 
insect problems. Internatl. Soc. Sugar Cane Technol. Cong. 
Proc. 6: 421-426. 
Many native parasites and predators are very limited in distri- 
bution, although conditions are favorable for them over a wide 
area, in which they can be successfully liberated. Parasites that 
have been used in this way in the United States are Aphelinus mali, 
against the woolly apple aphid. 
Cox, J. A. (252) 
A preliminary report on the woolly aphids of apple and hawthorn. 
Jour. Econ. Ent. 32(4): 477-483. 
Aphelinus mali was not reared from Eriosoma crataegi Oestl. 
in field collections and would not attack this species when caged 
in the field or in the laboratory. Infestations of E. lanigerum 
on hawthorn were often located by observing parasitized individuals. 
Haegele, R. W. (253) 
/ Aphelinus mali Hald^y Idaho Univ. News Let. 22: 3. 
Liberations of the woolly apple aphid parasite were made in 
the orchard at Parma during 1935 and 1936. It seemed to establish 
itself readily, for in the fall of 1936 practically all the exposed 
woolly apple aphids were parasitized. The effectiveness of this 
parasite in Washington and Oregon is noted, with the hope that it 
will be equally effective in Idaho. 
Lundie, A. E. (254) 
The apple grower's insect ally. Farming in So. Africa, 1939, 
Rpt. 92, 5 pp. 
A brief review is given of the distribution of Aphelinus mali 
throughout the world from original sources in the United States. 
It was introduced into Sough Africa in 1920, and is now so effective 
where the woolly apple aphid is present that spraying is unnecessary 
in most orchards. 
