30 THE SUGAK-BEET WIREWORM. 
after molting. This is especially apt to be the case in the fall, when 
they are sluggish. 
Most of the larvse observed during 1912 molted twice. A few 
were seen to molt once, although it is possible that a molt might have 
been overlooked in a few instances. In the case of a few others it 
was thought that a third molt was seen, but this is doubtful. From 
this it is impossible to give even the approximate number of molts 
with any degree of accuracy, but present indications are that they 
molt at least five or six times. 
The Pupa. 
pupation. 
In about July or August the mature larvae become shorter, and 
while they are not more constricted between the segments, they have 
the appearance of being so, as the segments swell slightly in the middle. 
At the same time there is a sHght change in color, the entire larva 
appearing sickly and of a dirty yellow color. During this period 
the wireworms lose most of their activity, and whatever movements 
they make are slow and weak. When pupation is only a short time 
off they are quite helpless, and if their pupal cells are broken open 
they are unable to make new ones. Several which were taken in this 
condition were able to pupate safely, the operation taking place in 
a Janet ants'-nest cage. 
THE PUPAL CELL. 
The pupal cell is simply an enlargement at the end of the larval 
channel, and is slightly elliptical in shape. It is unhned but is 
quite smooth and the soil is well compacted. The depth of the pupal 
cell below the surface varies between 4^ and 9 inches, but most of 
those observed were at a depth of about 6 inches. It is apparent 
that the wireworms move . very little preparatory to pupating, as 
pupae are often dug up with the wireworms close to the old beet 
roots. 
SOIL CONDITIONS AFFECTING PUPATION. 
The pupae (PI. V) are unaffected by a little dryness, but if the soil 
becomes quite dry for a long period they do not emerge. Many 
healthy pupae were dug up in the field in soil which contained only 
a Httle moisture. Those which came through best under laboratory 
conditions were from cages where the soil was kept only moderately 
damp. Where the soil was too wet a large percentage of the pupae 
sickened and died. Those found dead under these conditions were 
attacked either by a fungus or a bacterium, or sometimes by both. It 
was not determined whether these organisms were parasitic or sapro- 
