68 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
It will be noticed that in all cases eggs and larvae up to three days old 
were destroyed. At seven days from 90 to 100 per cent were killed or 
disappeared, at nine, from 80 to 85 per cent, at fourteen, a big variation 
occurs and from this time the results cannot be considered satisfactory 
or dependable. 
No dead maggots were ever found in the field. When the treatment 
is applied many of the maggots may be observed endeavoring to get 
away from the area moistened with the liquid. In no case, however, 
have treated eggs ever failed to be destroyed. 
It will be seen from these experiments that considerable latitude in 
the use of corrosive sublimate is allowable and that even under adverse 
weather conditions there is no necessity of applying the treatment until 
•several days after the flies appear. We know from other experiments 
that this material, even though applied before the eggs are laid, remains 
effective for some time. The same may be said of such treatments as 
creosote or anthracene oil dust, but not quite to the same extent. Never¬ 
theless, the value of these latter materials in this connection is abundant¬ 
ly proven and experiments looking to their wider use are strongly in¬ 
dicated. 
Past President Dean was invited to preside. 
Past President Dean: The next paper is “Mercuric Chloride—'Its 
Use for the Control of Root Maggots in Cabbage Seed Beds,” by Hugh 
Glasgow. 
CONTROL OF THE ROOT MAGGOT IN CABBAGE SEED-BEDS 
(A Comparison of Methods) 
By Hugh Glasgow, Geneva , N. Y. 
Abstract 
Control of the cabbage maggot, Chortophila brassicae in western New York 
resolves itself largely into the protection of late cabbage while still growing in the 
seed bed. Comparisons of the mercuric chloride and cheese cloth methods are 
decidedly in favor of the former, as regards cost and adaptability, although the 
method has still to prove its worth during seasons of maximum abundance of the 
insect. Certain precautions must also be observed since there is danger of burning 
just as the young plants are pushing through the ground. No other materials tested, 
except tobacco dust, gave great promise of success. 
The cabbage maggot is often thought of primarily as a pest of early 
cabbage and cauliflower. However, in the cabbage-growing section of 
western New York, where the production of late cabbage is the rule, 
