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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
In the life-history studies, care had to be taken at all times to keep 
the cages moderately dry. When adults were placed in cages con¬ 
taining moist soil, oviposition decreased, and when they were placed 
in cages containing both moist and dry soil, they showed a great pref¬ 
erence for the dry soil. The larvae developed best in a slightly moist 
soil. When the soil was too wet to crumble nicely, the mortality in¬ 
creased greatly. 
Blaisdell (1910, pp. 64-65) makes some interesting observations on 
the effect of moisture on the adults of Eleodes in general. He says that 
the individuals making up the specific aggregate do not necessarily 
breed true to any intraspecific degree of sculpturing, as this is wonder¬ 
fully influenced by environment and food supply. The beetles that 
develop in an exposed or arid region where the body fluids are reduced 
to a minimum by evaporation during the latter stages and especially 
after the pupal skin is shed will have a comparatively smooth form of 
sculpturing. Conversely, beetles developing in a protected or moist 
region where the body fluids are conserved will have a more strongly 
punctured or strongly striate form. The dominant form of sculptur¬ 
ing is therefore determined by seasonal conditions, a hot, dry season 
producing a large number of the smooth forms and a cold, wet season 
the more strongly striate and punctured forms. There will also be a 
varying per cent of intermediate forms produced. 
Effect of Light. —The larvae of E. tricostata are negatively photo¬ 
tropic. When placed on the surface of the ground they immediately 
burrow into the soil. In all the studies so far made, larvae have never 
been found on the surface of the ground. The adults, like most of 
the species of Eleodes, are generally nocturnal or crepuscular in their 
habits. They seek to avoid light in the field by hiding during midday 
under rocks, logs and manure, and also in burrows of other animals. 
Measures of Control 
E. tricostata has not as yet become of sufficient economic importance 
to warrant any extensive experiments on control. The use of poisoned 
bran was tried, under laboratory conditions, on the adults with good 
success but the larvae lived for weeks on such a diet. With most of 
the injurious forms of Eleodes, it has been found possible to control 
them by summer fallowing the ground. This is a procedure that 
could be followed in western Kansas to a good advantage. Rotation 
is also recommended in some cases since the beetles are wingless and 
move only on foot. Hyslop (1912, p. 87) records his experience in 
treating seeds with various poisons to destroy the larvae. Five or six 
poisons and repellents were used, all with negative results. 
