32 
with respect to the habit of hibernation in the pupal chamber are, how- 
ever, needed to determine the value of this economic method for Dras-— 
terius elegans. 
THe WHeat WIrrREWworRM. 
(Agriotes mancus, Say.) 
(Plate V., Fig. 4-6.) 
This larva, commonly known as the wheat wireworm, is injurious 
to corn as well as to small grain. It is a cylindrical pale brownish yel- 
low species, readily distinguished from any other wireworm (except 
another species of the same genus, doubtfully separate) by the smooth 
outlines of the last segment of the body, (which is slightly pointed at 
the tip), and especially by two conspicuous black circular pits upon 
the upper surface of this segment near its front border. 
It was first found by me in corn fields July 1, 1883, in a field near 
Peru, Illinois, which had been broken up the preceding year from sod. 
Specimens collected here were devouring the roots of the corn and per- 
forating the stems just above the roots, the plants being at the time from 
eight to twelve inches high. The effect of this attack—especially of 
the perforation of the stems—was shown by the sudden withering of the 
infested stalks. About six per cent. of the corn in the field had already 
been killed in this way. It was further obtained by us April 27, 1886, 
in an old corn field among specimens collected by following a plow. 
July 4, 1889, it was sent to us from Prophetstown, Uhnois, with a 
report of serious injury to corn and potatoes, plants of which withered 
and died under the attack. A field of one hundred acres over which 
they seemed well distributed, was reclaimed swamp land, recently — 
> b) 
brought under cultivation. Finally, | found it near Sycamore, Illinois, 
on the 11th of July, 1889, in a field tiled and drained the year before 
and broken up in September from a marshy sod. In this field it had 
completely killed the corn in small patches, and notably crippled its 
growth in others. 
The larva has further occurred in our collections from pastures and 
meadows at Champaign. It is not nearly so abundant in Illinois as 
some other wireworms, only about one eighth of our office collections 
representing this species. In New York, however, it seems to be the 
commonest wireworm known, making ninety-one per cent. of some 
10,000 larve sent to Professor Comstock, of Cornell University, for 
experimental uses. 
It has been aes as a corn Led only in a brief note in“In- 
sect Life” (Vol. III., p. 246), by Mr. C. A. Hart, an assistant of this 
office, whose tener: was based upon our breeding-cage work and col- 
lections. 
Its injuries to wheat, though doubtless occurring in Illinois, have~ 
not come to the notice of myself or my assistants. It has, however, been 
reported from wheat fields in Indiana by Mr. F. M. Webster,* infest- 
* Rep. U. S. Dept. Agr., 1887, p. 153. 
