38 
early in spring, when they begin to eat again after this long- 
fast, that the greatest damage is done to crops. 
Larvae become full grown and pupate in July, in earthen cells 
the change occurs a few days after these cells are formed, and 
pupae ai e most abundant about the middle of July. Adults mav 
be found by the end of this month, and by about September 1 
all the pupae have changed to beetles. For a few days after the 
change the\ are yellowish white in color, and nearly as tender 
as pupae. Before winter, however, they have become hard and 
normally colored. In Comstock’s experiments, the beetles passed 
the vintei in their earthen cells, none coming to the surface the 
same fall unless their cells were injured. Adults thus disturbed 
did not form new cells, but worked their way to the surface and 
soon died. In April the greater number of the beetles emero*e 
from the earth, though we have taken them almost continuously 
from March 22 to the middle of July. They are most active 
in the evening or at night. 
Description. Larva. (Plate V., Fig. 5 and 6.)—“The newly 
hatched larvae must be very small, and, according to European 
writers, they grow very slowly. The smallest larvae of the 
wheat wireworm we have seen were about 4 mm. in length. 
All variations in size occur at the same time up to a full grown 
larva, which measures from 16 mm. to 19 mm. The larvm are 
quite slender, cylindrical, somewliat flattened on the venter, 
sparsely hairy, and of a waxy yellow color, lighter at the 
sutures. The anal segment tapers gradually to a subacute brown 
point, and bears on the dorsal aspect, near the cephalic border, 
two large conspicuous, brown, eveJike depressions resembling 
the breathing pores. By these, the wheat wireworm of any size 
may be readily separated from any other species which we*have 
found infesting fields.”* 
Pupa—“The pupa resembles the imago in many of its char¬ 
acters, being, however, about one fourth longer, and in the ab¬ 
dominal region more slender, the only differences of moment 
being the following: 
thorax at each angle with a stout bristle-like appendage 
more slender towards the tip, about a sixteenth of an inch long. 
That at the anterior angle is supported on a small papilla, the 
posterior being prolonged from the tip of the angle. Terminal 
abdominal segment above subquadrate, emarginate at tip, 
angles acute and divergent, beneath with a deep sinuous groove 
on each side and a median shallower groove. 
Abdomen above and beneath of nine segments, the first very 
narrow, distinctly visible above, beneath visible only at the 
sides; second slightly broader, beneath nearly entirely concealed. 
The remaining segments are distinctly visible both above and 
^Comstock and Slingerland, in Bull. 33 Ent. Div. Agr. Exper. Station. Cornell Univ.. 
