37 
The form of the thorax clearly distinguishes this species from the 
others attacking corn. The legs and antenne are chestnut-red. 
Tup Corn WIrREWORM. 
(Melanotus cribulosus, Lec.) 
(Plate VI., Fig. 6-8; and Plate VII., Fig. 1.) 
This is without doubt by far the commonest wireworm in corn 
fields in Illinois. Larve referable to it make not less than one third 
of the wireworm collections of this office, and fully half of these were 
taken in corn fields at dates from April 27 to June 28, that is to say 
during the time when wireworm injury to corn is generally commonest 
and most serious. On the other hand, the adult is far outnumbered by 
M. communis in miscellaneous collections, being, indeed, rather rare 
with us except among insects obtained from corn fields or bred from 
larve infesting corn. Le Conte found the species in Nebraska, and 
Smith’s Catalogue of the Insects of New Jersey credits it to that state. 
Little has been added to our knowledge of this species since I pub- 
lished in 1886 a brief account of its life history in my Miscellaneous 
. Essays on Economic Entomology (p. 17). The statements of that article 
| were based chiefly upon observations made in 1885 in a field of corn in 
~ Champaign county which had lain in pasture for many years before. 
¥ The injury to which corn is liable when the ground is infested by 
this species was well illustrated by the condition of this field, where 1 
| estimated that wireworms averaged three to a hill for the entire area, 
the number ranging from two to six or eight. Only about one hill in 
fifty was found free from them in the higher, more sandy, parts of the 
field, although on the lowest ground there were no wireworms at all in 
several hills examined. They had attacked only the kernels as yet, but 
would later, of course, have eaten the roots and burrowed the under- 
ground portions of the stalk. All the wireworms in this field were 
. concentrated in the hills of corn, not a single one being found during 
protracted search made elsewhere. Even the few remaining tufts of sod 
of the preceding year were free from them where the hills around were 
badly infested. The ground had been in corn the year before, and had 
then been considerably damaged, but not nearly as much so as at the 
time of my visit. It had, however, been replanted about June 1 (1884), 
and the owner was plowing up the first planting May 25, 1885, with a 
| view to planting again. 
The wireworms taken from this field were easily assorted in two 
al 
lots, and only two, according to size. Placed in breeding cages May 
. 25, they were still living as larve June 13 and July 12. By August 3 
pupation had begun, the pupe being enclosed in elongate cells in the 
earth, and on the 22d pupe were again found, but no imagos, while 
_ September 12 pupx, recently transformed imagos, and others of a color 
and consistency to indicate that they had changed at least a few days 
‘previously were found still in the earth. None of the beetles came out 
of the earth in the cage during early fall or winter, but February 17, 
1886, all were found dead in their pupal cells, badly infested by mites. 
The larvee of the smaller size were not bred in this experiment, but only 
those seemingly full grown. All the specimens reared were cribulosus, 
