April, ’18] 
BALLOU: PINK BOLLWORM 
241 
For the control of this insect it is necessary to destroy the resting- 
stage larvae at the end of the cotton season. This work falls naturally 
under two headings—the destruction of all bolls left in the field after 
the crop is harvested and the destruction of the larvae in the cotton seed 
after the cotton is ginned. 
Control Measures 
In Egypt a law has been passed requiring the destruction of the 
bolls on the plants and of all that may have fallen to the ground imme¬ 
diately after the crop is finished. A law has also been passed requiring 
that every ginnery shall be provided with a suitable machine for the 
treatment of cotton seed as it leaves the gins, for the destruction of the 
pink bollworm larvae in the seed. 
On account of the difficulties which arise from the war, in obtaining 
the necessary machinery, this law has not yet been put into force. 
Experiments have been made, however, with machinery for the treat¬ 
ment of seed by means of heat and there appears to be no difficulty 
in killing all the worms in the seed without affecting the quality of 
the seed either for the purposes of planting or for the production 
of oil. 
The use of hydrocyanic-acid gas and carbon bisulphide does not 
seem to be practicable under the existing conditions in Egypt. The 
highly poisonous nature of hydrocyanic-acid gas requires the employ¬ 
ment of careful and responsible labor in its application and this is not 
to be had in the ordinary way in the cotton ginneries in Egypt. Fur¬ 
ther, it is objected that in such a densely populated country the libera¬ 
tion of large quantities of poisonous waste gases would be likely to be 
injurious to public health. Carbon bisulphide, on account of its 
highly inflammable and almost explosive character, is not suitable for 
use in close proximity to cotton ginneries where the atmosphere is 
laden with the fine particles of cotton which, in the event of fire, are 
also highly inflammable. 
As far as Egypt is concerned, hot air seems to be the most suitable 
agent for the destruction of the pink bollworm in cotton seed at the 
ginneries. 
The pink bollworm campaign which is carried out under the direc¬ 
tion of the Ministry of Agriculture has for its object the destruction of 
the bolls left in the fields after the crop is harvested. The season of 
1916-1917 was the first one in which this campaign was well organized 
and thoroughly carried out. The results obtained from this campaign 
although not altogether satisfactory have been very useful. A very 
large proportion of the bolls were destroyed. 
The law required that the bolls should be cleaned from the standing 
