Dec. i 5 ,1923 Biology of Eleodes suturalis 559 
around straw or grain stacks or other shelters, and have been found in 
the moist soil far under such straw stacks beneath a layer of straw 
5 feet in depth. In fields recently sown to wheat they are usually 
disseminated irregularly over the field, but are in greatest numbers near 
the shelters, and are sometimes in such abundance that as many as 
265 larvae of this and related species have been found in three adjacent 
drill rows within 3 linear feet. 
Cannibalism is rather common, both under artificial rearing and under 
normal field conditions, and where the larvae are abundant in a field it is 
not uncommon to find numbers of partly devoured larvae here and there 
at the spots of their greatest activity. This is most noticeable, however, 
under field conditions during the early period soon after germination of 
the grain, when the larvae are most busily feeding and where conditions 
may be such as to produce crowding. Under average field conditions 
sufficient numbers of larvae are not destroyed in this way, however, to 
render cannibalism a factor of value from an economic standpoint, as this 
larva is normally phytophagous. The larva appears sensitive to dis¬ 
turbance of any kind. If touched it will often feign death and remain 
motionless for a time before attempting to escape. If taken between 
the fingers, the pressure sufficient to hold it causes it to make the most 
frantic efforts to escape, and it twists and wriggles its body with greatest 
activity into almost every possible position, ejecting quantities of a 
colorless fluid apparently from between its dorsal segments. Presumably 
this fluid is defensive or repulsive and is one of its means of protection 
from birds and other enemies of similar feeding habits. 
The larva, being very quick and active, can move easily over smooth 
surfaces and bury itself in the loose soil with greatest ease. It is able 
also to penetrate compact soil with little apparent difficulty, since it has 
been found working in ground of considerable hardness at a depth of 
2 inches, but if the soil be fairly loose, its friableness and dryness appear 
to facilitate larval movements. When very young it is unable to survive 
long in perfectly dry earth, but as it becomes larger it does not appear 
to be greatly affected by this condition, although it prefers slightly moist 
soil. The larva is keenly susceptible to an overabundance of moisture 
and often comes to the surface of the ground and remains there for several 
hours following hard, dashing rains. It is negatively phototrophic and 
when exposed to light hides with the utmost rapidity under any shelter 
it can find. When artificially confined in a Petri dish, it soon crawled 
beneath the layers > filter paper or blotting paper at the bottom of the 
vessel. 
When ready to molt the larva remains comparatively motionless for 
some time before the skin splits and it is able to free itself therefrom. 
Molting occurs in its channels, and wriggling from its exuvia, the larva 
remains comparatively inactive for a short time until the new skin 
has hardened somewhat. Considerable difficulty was experienced in 
obtaining the length of instars, as it was necessary to do this under 
laboratory conditions, and a number of types of cages were tried and 
discarded before one suitable for the purpose could be evolved. The 
irregularity in time of molting, the proper regulation of food and mois¬ 
ture, and the difficulty of finding the exuviae in the cage also added to 
the complexity of the problem, and many hundreds of larvae died in 
various forms of cages and through a variety of causes before the desired 
information could be obtained. The type of cage from use of which 
satisfactory data at last were secured consisted of a 2-ounce, seamless, 
