THE ROUGH-HEADED CORN STALK-BEETLE ll 
extremely troublesome, and it required the utmost vigilance to pre- 
vent its gaining access to the breeding boxes. According to Mr. 
Banks, the mites are saprophytic upon decaying vegetable matter, but 
whatever may be their normal feeding habits, it 1s the uniform ex- 
perience of the writers, as well as of others who have worked with 
white grubs, that the presence of these mites in the breeding boxes is 
highly detrimental to the larve. Ali soil or vegetable mold for use 
in breeding boxes was thoroughly fumigated with chloroform to kill 
all mites. Boxes infested with mites were emptied and sterilized in 
boiling water. To remove the mites from the larve the latter were 
gently, but firmly, held between the thumb and index finger of the 
left hand and the mites leosened and brushed off under a binocular by 
means of forceps. Sometimes, to facilitate the removal of the mites, 
the larve were plunged for an instant into a very weak solution of 
formaldehyde and then quickly washed in tap water. This treat- 
ment appeared to cause the mites to adhere iess tenaciously to their 
host, and also had a quieting effect upon the larva. 
For some reason—possibly the prevailing low temperatures of the 
season—these and other species of mites appeared to be unusually 
scarce in 1916, so that during that year these precautions were found 
unnecessary. 
FOOD AND FEEDING HABITS 
The experience of the writers both in the laboratory and in the 
field indicates that the normal food of the larve consists chiefly of 
decayed and disintegrated vegetable matter. This vegetable mold 
does not usually occur as a distinct layer, being intimately inter- 
mixed with the surface soil; but in the particular pasture of Tappa- 
hannock where most of the collecting was done the mold had accumu- 
lated as a practically pure layer on the surface wherever the plant 
cover was sufficiently dense to protect it from wind and from the 
trampling of stock. This would be particularly true of old pastures 
that had not been tilled for a number of years. Vegetable mold of 
the finest consistency usually occurred under the low, matlike growths 
of Japan clover (Lespedeza striata), wherever these were dense 
enough to afford it adequate protection. In the layer of vegetable 
mold, or in the soil immediately underlying it, larve of H'uetheola 
rugiceps in all stages of growth were found in abundance, particu- 
larly where it was associated with clumps of Paspalum, a circum- 
stance that is doubtless connected with the fact that these grasses 
constitute the usual food of the aduits. 
In most other localities where the larve were found the layer of 
vegetable mold was not as extensive or as clearly defined as in the 
pasture at Tappahannock. The favorite haunts of the species ap- 
pear to be low or poorly drained areas where the plant growth ap- 
proximates that characteristic of the borders of marshes. In such 
areas the accumulation of vegetable detritus is relatively rapid. 
Attempts were made both at Tappahannock and at Charlottesville 
to rear the larve upon cow manure in various stages of decay. Fresh 
manure appeared to be highly injurious to them, but old, dry, and 
‘well-cured manure, when slightly moistened, proved fairly accept- 
able, although the mortality among the larve fed in this way was 
excessively high. It would seem probable that, while the vegetable 
constituents of manure may be suitable for the larvee, other portions 
