146 
Psyche 
[June- August 
PRELIMINARY EXPERIMENTS FOR THE CONTROL OF 
CERTAIN EUROPEAN VINE-MOTHS BY FUMI- 
GATING WITH CYANOGAS CALCIUM 
CYANIDE. 1 
By S. M. Dohanian, 
Somerville, Massachusetts. 
In western Europe there is no fruit cultivated as extensively 
as the grape. Travelers there are at once impressed by its 
general culture. Vineyards are exceedingly common in Portugal, 
Spain, Italy, France, Switzerland and western Germany, the 
parts of Europe with which the writer is familiar. It is natural, 
of course, to assume that a plant as common as the grapevine 
must have a large number of insect enemies. And it has. There 
are more than a dozen insects which may be considered of 
economic importance. The most notorious of them all, however, 
are two small Tortricids, commonly known in Europe as Co- 
chylis ( Clysia ambiguella Hb.) and Eudemis ( Polychrosis botrana 
SchifL). 
Records show that for more than two centuries these two 
pests — and they are pests in the full significance of the word — 
have been present in the vineyards of Europe. Over a period of 
many years the annual loss to the vineyardists in each of the 
countries mentioned above has been millions of dollars. Owing 
to this enormous damage they have been the subjects of study 
by various noted entomologists in these countries, but till now 
no effective method of control has been discovered. 
The investigations of the writer in the winter of 1925-26 
brought forth the interesting information that thse two in- 
sects are unable to survive a dry season. While he was in Spain 
during the spring and summer of 1924 he was witness to a severe 
drought lasting from mid-April to late that autumn. This dry 
spell had reduced their numbers more than 95% for the season 
of 1925. The month of January, 1926, was spent in an exhaustive 
1 In November, 1925, the American Cyanamid Sales Co. of New York, 
sent the writer, who was then in their employ, to Europe to investigate the 
possibilities of Cyanogas calcium cyanide being used for the control of the 
vine pests mentioned in this article. 
