22 
THE SUGAE-BEET WIEEWOEM. 
but it soon gave promise of being a simple and safe receptacle in 
which, to rear wire worms. 
The other style of cage was the common root cage (PL VIII, -B.g. 2), 
so often used for the study of underground msects. The cages used 
in these experiments had the glass walls very close together (one- 
eighth to one-fourth inch) so that there would not be much soil m 
which the larvae could hide. The root cages were not so successful 
as it was hoped they would be, for the larvae were usually able to 
conceal themselves and 
it seemed almost im- 
possible to wet the 
cages properly. Used 
in conjunction with the 
other cages, however, 
they gave fah success. 
The majority of the 
young wireworms were 
kept in large flower- 
pots, so that in case of 
accidents to the rearmg 
cages not all the larvae 
would be lost. These 
pots had an added ad- 
vantage in that they provided soil conditions quite similar to those 
out of doors. The flowerpots were emptied and exammed from time 
to time so that the larvae could be watched. 
Fig. 5. — Janet ants'-nest plaster-of-Paris cage, used in rearing 
sugar-beet wireworms. A, compartment for larvae; B, com- 
partment for water. (Original.) 
HABITS OF THE YOUNG WIREWORMS. 
The young wireworms are quite active, moving over smooth sur- 
faces or burying themselves in the loose soil with ease. Some placed 
in a root cage buried themselves almost at once, but were tempora- 
rily checked b}' a la3'er of compact earth about an inch below the 
surface. On the following day several had entered the compact 
layer and the next day one was noted at a depth of 4 inches. 
T\lien ver}' young the}' are unable to survive in dry earth even for 
a relatively short time. Some which were placed m a petri dish 
with dry soil were dead at the end of five hours, a few dying after the 
first hour and a half. 
These larvae shun the light and when exposed to it hide under any 
object which they can find. TThen placed in the petri-dish cages 
the}^ soon crawl between the layers of filter paper at the bottom. 
Experiments were made to test their ability to locate food, by placmg 
a slice of sugar beet m the cages and noting the time it took them to 
collect under it. The beet slice was not larger than a dollar and was 
