40 
concerning the life history and habits of the insect, and to verify or 
disprove what had been previousl}^ written concerning these points. 
The results of this investigation b}^ Professor Mally are presented in 
Bulletins 24 and 29, old series, of the Division of Entomology, and 
were issued in 1891 and 1893, respectively. 
Many detailed observations on the injuries to corn, cotton, and other 
plants were made, and a S3^stematic series of experiments was con- 
ducted with various insecticidal substances in order to determine their 
possible value in bollworm control. The value of corn as a trap crop 
is demonstrated and a definite plan is presented for its utilization by 
planters. Experiments with bacterial diseases were conducted, and 
the uselessness of attempts to attract moths to lights and poisoned 
sweets, as previously recommended, is pointed out. The reports 
together cover 123 pages, and bring together the important facts then 
known concerning the cotton bollworm and present for the first time 
results of any considerable experimental work. 
Frequent mention has been made of the bollworm as injuring cotton, 
corn, tomatoes, or other crops in the bulletins and reports from the 
office of the Entomologist of this Department, and recently (1896) a 
full account of this species, by Dr. L. O. Howard, has been distributed 
in Bulletin 33 of the Office of Experiment Stations,^ which was issued 
in revised form in 1897 as Farmers' Bulletin 47, "Insects affecting the 
cotton plant.'' 
In spite of the work of the Department on the bollworm, but little 
progress had been made by the planters in its control. The recent 
increase of the ravages of the pest in certain parts of the cotton belt, 
notably in Texas, led to provision by Congress for another investiga- 
tion, and the present paper is a final report on this the fourth specific 
investigation of the species. The present investigation was begun in 
the spring of 1903, and continued to December 31, 1904. Reports of 
field work have already been published in Farmers' Bulletins 191 and 
212 of this Department. 
LIFE HISTORY. 
SUMMARY. 
The eggs of the bollworm (PI. Ill, fig. 1) are deposited by the boll- 
worm moth upon the food plants of the larva?, which are preferably 
corn and cotton, or less commonly tomato or tobacco. Each female 
ma}^ lay from 500 to 3,000 eggs, which she deposits singly in a more 
or less promiscuous manner over the plants, more especially on the 
silks of corn and the squares of cotton. During the warmer parts of 
summer the eggs hatch after two or three days and the larvae begin 
feeding. On corn they attack the tender bud in the spring and the 
«The Cotton Plant, pp. 328-333. 
