133 
MECHANICAL DESTBUCTION. 
Various types of machines for collecting cotton boll weevils from 
plants have been devised during the past few years. Some of these 
have been tried for collecting the cotton boUworm (see PL XXIV, 
iig. 2). In one case it was determined by a series of counts that about 
10 per cent of the bollworms were collected by the machine in passing 
over the plants. It is considered possible that machines of this char- 
acter may be so perfected as to render their use profitable in collecting 
bollworms. 
METHODS OF BOLLWORM CONTROL ON CORN, TOMATOES, AND 
TOBACCO. 
It must be acknowledged that thus far no satisfactory method of 
controlling the boUworm on sweet and field corn has been discovered. 
In those States where the insects hibernate in corn fields fall or winter 
plowing would be especially valuable in destroying the pupse in the 
soil. Indeed, this practice is about all that may be recommended. 
During the present investigation tests have been made of several plans 
which have been recommended as of possible value. The plan to 
crush larvae in the roasting ears, by hand or otherwise, does not, 
apparently, take account of the often numerous smaller larvae to be 
found in the ear and which largely escape the eff'ects of pressure fatal 
to the larger individuals. 
Tests by Messrs. Bishopp and Jones of various substances placed 
on corn silks and ears, as black pepper, tar, sulphur, tobacco, crude 
petroleum, pennyroyal, creolin, pyrethrum, etc., as repellents to the 
moth in egg laying on these parts, gave negative results. While 
some substances apparently prevented the moths from ovipositing, 
their effect was to kill the portions treated. 
The first brood of larvae infesting ''buds" of corn in the spring 
could in many instances be profitabl}^ sought for and destro3^ed by 
children, or plow hands in the course of their work, thus greatly 
lessening the numbers of the insects in succeeding generations. This 
practice uniformly followed by the farmers of a neighborhood should 
serve in the course of a year to so reduce the numbers of the bollworm 
that its injuries would be of little importance. Such a plan would be 
perfectly practicable in lessening injury to cotton, and its value would 
be in proportion to the extent of its adoption by the planters of a 
neighborhood. 
No experiments in the control of the bollworm on tomatoes were 
undertaken during the present investigation. While there are but 
few data as to the deposition of eggs by the bollworm on tomato 
plants, it is certain that these are placed quite as promiscuously over 
the leaves, stems, etc. , as was found to be true in the case of cotton 
