326 Journal of Agricultural Research voi. xxu, no. 6 



HABITS 



The larvae are exceedingly active and quick and, if exposed to light by 

 the plow or otherwise disturbed, have the power of ^vriggling very 

 quickly down out of sight into the soil. They are also occasionally 

 found upon the surface of the ground feeding upon seeds of weeds and of 

 other plants, in spots where the soil may be slightly moist and where 

 they are covered by wheat shocks or by matted masses of dried Russian 

 thistles or other weeds. While they appear to prefer habitats where 

 there may be a slight degree of moisture, such as moist, poorly drained 

 spots in fields, and cool, damp cellars, yet they do not live long in thor- 

 oughly wet soil. Both larvae and adults often may be found in numbers 

 beneath dried weeds along irrigation canals. The larvae habitually feed 

 during warm weather at a depth varying from 2 to 5 inches, according to 

 condition of the soil. As they burrow from place to place, they feed upon 

 the roots and seeds of plants, and possibly to a certain extent upon 

 organic matter where this is sufficiently decayed. When placed under 

 artificial conditions the larvae feed readily not only upon germinating 

 wheat, but upon com and roots of grasses. They are cannibalistic in that 

 they feed upon other larvae of the same species which die or become 

 weakened because of injury or disease. They also feed upon their own 

 exuviae. 



The adults, in common with those of other nearly related species, are 

 very hardy and active and appear to be able to withstand considerable 

 variations of temperature. While they, like the larvae, appear to prefer 

 cool, moist spots, they do not survive temperatures as low as —9° F. 

 They have been collected in August beneath wheat shocks in fields where 

 the temperature was as high as 100°. The adults easily climb all over 

 wheat where standing or in the stack or shock, and they burrow with 

 apparent ease far into the piles of unthrashed grain. They are also fre- 

 quently found in the burrows of small mammals. During periods of pro- 

 longed drought the beetles may seem to have entirely disappeared, yet 

 immediately following a shower or rainstorm, curiously enough they 

 reappear in large numbers, where previously none could be found. 



DESCRIPTIONS 



EGG 



Size slightly variable, being i.i to 1.3 mm. in length and 0.60 to 0.62 mm. in width; 

 shape circular in cross section and oval in longitudinal section; without sculpturing; 

 color pure white when first deposited, changing to yellowing brown before hatching. 



MATURE LARVA * 



Length 27 mm.; color testaceous with head and legs somewhat darker; anterior 

 and posterior margins of prothorax and posterior margins of the following segments 

 castaneous-testaceous. Surface corneous. Form elongately cylindrical, more than 



1 Description and Plates 31 and 32 by Adam G. Bdving. 



I 



