36 
THE SUGAE-BEET WIEEWOEM. 
In one field, which had a great many old beets on the surface, the 
beetles were taken from under almost every on'e, and sometimes in 
large numbers. It was a common matter to find from 30 to 70 
adults under single beets, and as many as 243 have been found hiding 
under one beet. Another favorite shelter was afforded by the old 
beet tops (PI. XVIII) left in the field from the previous year's harvest. 
In the field which adjoined this one there were few or no old beet 
tops and beets for shelter, and here beetles were rarities. This field, 
just the year before, suffered more than any of the surrounding fields 
fro m ^\ireworm in- 
jury, so there must 
have been beetles 
which developed from 
the mature wire- 
worms that had 
caused the damage. 
In other fields, how- 
ever, which had suf- 
fered similar injury 
but m wliich the old 
beets had been al- 
lowed to r e m a i n , 
beetles were present 
in 1 a r g e numbers . 
There seems to be 
only one explanation 
for this fact, and that 
is that the adults had 
emerged from the 
cleaned fields and, not 
finding any shelter, 
had been obUged to 
move to other fields 
or be destroyed by 
the birds. This was further indicated by the fact that all the beetles 
found in the clean fields were mo\nng about. The state of aft'airs 
was found to be the same in other fields aggregating over 600 acres, 
where the conditions were similar. 
Fig. 8. — Screen cage used in obsennng oviposition of adults of the 
sugar-beet Tvireworm under field conditions. (Original.) 
STYLES OF REARING CAGES USED. 
Several styles of rearing cages were used, but only a few will be 
considered. The ones used indoors consisted of batter}^ jars, flower- 
pots, and flowerpots mth lantern globes. The highest death rate 
was found in the first, because there was no drainao-c and the contents 
