INJURIOUS INSECTS OF 1909 AND IQIO. 43 
CONTINUATION OF WORK WITH CABBAGE MAGGOT IN 1909. 
A large amount of work, representing many experiments, was 
carried on in 1909. Much of this work resulted negatively, but is 
deemed valuable in showing what is not effective, or what may be 
detrimental to the plants, although efficacious in keeping off the 
maggots. Much of this work is given here in detail. 
Summarizing from results we can state that: 
1. Tarred paper discs were found very effective. See p. 47. 
2. Sawdust and glue were fairly efficacious, p. 49. 
3. Treatment with carbolic acid emulsion, p. 54, gave excellent 
results. See also results with tobacco dust, p. 55. 
On May 14th cauliflower plants were set out south of the insec- 
tary. On May 18th a row of these cauliflowers, containing 51 
plants, was treated with O. & W. Thum Company’s tree tanglefoot 
(brand R2). This was applied by first melting the tanglefoot in a 
tin pail, and applying it around the bases of the plants on the 
ground, when it had cooled to a temperature of 130 degrees Fah. 
It is probable that, before the application was finished, the tempera- 
ture of the tanglefoot had got down as low as 110 degrees Fah. 
The tanglefoot was used at the rate of about one pound for 32 
plants, and costs about 25 cents a pound, so that the material cost 
a little less than one cent a plant; which would make the cost of 
material for treatment of an acre extremely cxpensive. But the 
treatment was carried on with the hope that material might be 
obtained at less expense for this purpose if it was found to prove 
satisfactory. 
On May 28th this row was examined, and it was found that 38 
out of 51 plants used in the experiment, or about 75 per cent., had 
died on account of the treatment; but it was noticed that the plants 
stood the treatment all right in case the tanglefoot was not placed on 
the leading leaves. Of the 13 living plants 4 died later, so that 
on June 15th only 9 healthy plants were left. These were pulled 
up on June 15th, and all of them were almost entirely free from 
infestation, and only three were infested at all. The general 
results of the experiment may be said to be negative aside from 
showing that the tanglefoot will stop the maggots. 
On May toth cauliflowers, which had been planted below the 
Dairy Hall on May 14th, were also treated with O. & W. Thum 
Co.’s tree tanglefoot (Brand R2). The tanglefoot had to be 
