Dec. 15, 1923 
Biology of Eleodes suturalis 
55i 
has become in large part their food. Of these introduced plants, the 
insect in the larval or adult stage, or in both stages, is known to feed more 
or less upon the following: Wheat (Triticum vulgare Vill.), oats ( Avena 
saliva L.)> corn (Zea mays L.), rye (Secale cereale L.)» millet (Setaria 
italica Beauv.), alfalfa (Medicago saliva L.), kafir (Holcus sorghum L-), 
fleshy roots of sugar beets (Beta vulgaris L.), and several garden crops, 
notably the bean (Phaseolus vulgaris L.), and tubers of the potato 
(Solarium tuberosum L.). So far as known, wheat appears to be its 
favorite food, and this crop seems to suffer most from the depredations 
of the insect. Curiously enough, the injury to wheat is so great, and that 
occurring in the other crops enumerated is so slight by comparison, that 
a rotation introducing some of these crops, as will be shown later, has 
proved to be an efficient control measure. Although the beetle is known 
to feed to a greater or less degree upon practically all of the food plants 
enumerated, the greatest injury is wrought by the larva. 
CHARACTER OF INJURY 
The principal infestation of wheat occurs in the fall soon after sowing. 
As soon as the grains commence to soften in the process of germination, 
they are attacked by the larva. At times two or more larvae may attack 
a single grain, and eat out its entire contents, leaving only the empty 
husk, but more often only one larva was found feeding upon a grain. The 
characteristic nibbling of the ends and gnawing out of the germ of the 
grain by the larva when once seen may afterwards be easily recognized. 
The young sprouts are also occasionally injured, though even when not 
attacked they wilt and die as soon as nourishment is no longer obtainable 
from the infested grain. When the plant is not attacked until well 
sprouted, the results are quite similar. Even the most vigorous plants 
seldom if ever put forth new roots. 
In the fall the infestation is often confined to the more impoverished 
areas in a field, but in spring the larvae may be present in numbers among 
the roots of tall and apparently healthy plants in the more productive 
areas. Where the surface is of a rolling character, infested fields soon 
present, in the fall, a parched or spotted appearance, the knolls standing 
out at first distinct and bare, although before harvest they become over¬ 
grown by grass and weeds. After the wheat has grown up somewhat 
around these devastated spots, the bare areas often become filled with 
dried thistles, blown there by the wind. 
In addition to the injury caused by the larva, wheat in the shock or 
stack is damaged noticeably by the adult, which nibbles the ends of the 
grains. 
The maximum injury to fall-sown grain occurs almost invariably 
during years when normal moisture is lacking. Frequently in the sandy, 
arid districts there are no rains during early fall, and the seed wheat lies 
in the ground for weeks after seeding. It is during these protracted dry 
seasons, while the grain is unable to sprout, that the larva is most inju¬ 
rious. During seasons when sufficient moisture is present at seeding 
time to cause the plants to sprout at once, less damage is done. 
In only one year thus far, namely, that of 1910, has the pest invaded 
in destructive numbers the eastern portion of the area indicated. In the 
early summer of that year large numbers of adults were found in that 
area in the vicinity of straw stacks and beneath old weedy wheat bundles 
which had been discarded from the previous harvest. These waste 
