THE DIFFERENTIAL LOCUST. 
destroyed. It was demonstrated that for such condition- this i- one 
of the most satisfactory methods for quickly checking the injury over 
a -mall area. 
Cause of 190^ outbreak. — In the summer of 1902 the Brazos River 
overflowed in a most unusual manner, and again in February, L903, a 
smaller overflow occurred. This resulted in large area- throughout 
the lower Brazos valley remaining uncultivated in 1903. This hard- 
packed soil gave ideal conditions for ovipo-ition. and the weed- which 
came in furnished the favorite food of the hoppers, thus making their 
rapid multiplication certain. That an unusual outbreak should occur 
in the spring of 1904 was therefore to be expected. Throughout the 
bottom lands of central Texas this species is always common, and does 
more or less damage along the edges of the corn and cotton fields: but 
ordinarily the planters disregard the injury and allow the pest to 
multiply. Then, when such condition- as those above outlined occur, 
the pe-t increases very rapidly and serious injury is widespread. 
Were the weeds around the edge- of the held- dusted with an arsenical 
whenever grasshoppers are observed to be common, and were uncul- 
tivated areas plowed during the winter when possible, the num- 
bers would be so reduced that such outbreaks would not frequently 
occur. These conditions were exactly similar to those mentioned by 
Professor Morgan" concerning the outbreak of this species along the 
Mississippi, after a crevasse had been formed in the levee and a con- 
sequent overflowing of the adjacent land had resulted. 
f's, of fungous diseases. — Cultures of the fungous diseases with 
which experiments have been made in recent years asa means of com- 
bating locust- were secured from several sources. The tube- received 
from Prof. Lawrence Bruner. of Nebraska, mentioned below, were 
stated to contain what was probably a species of Mucor. Those 
received from Prof. C. P. Gillette, of Colorado, had been sent him by 
Doctor Edington. of the Bacteriological Institute. Grahams town, (ape 
of Good Hope. Those from the Bureau of Entomology were marked 
"•Culture C." and were also of South African origin, although pre- 
pared by the Department of Agriculture. These cultures were han- 
dled according to the direction- sent with them, 8 and locusts dipped in 
the prepared solution were freed where they were most abundant in 
the field. Corn meal moistened with the solution was also scattered in 
these localities. These distributions were made on April 1!'. at four 
points, several mile- apart. Examinations on April 29 and May '.♦ failed 
to reveal any grasshoppers dead from disease, nor did the planters see 
any later in the season. After May I the locust- had been SO depleted 
' 1901: Bui. .'HI i). b., Div. 1 : 1 1 1 . . K. s. Dept. Agric, p. 31. 
&See Howard, Yearbook IT. S. Dept. Auric, t. 1901, p. 464; and Bruner, Bui. 38, Div 
Knt.. K. S. Dept. Agric, p. 50. 
