18 
THE WHEAT-BULB WORM. 
(Meromyza americana, Fitch.) 
Order Diptera. Family Oscintpm. 
Synonyms: The American Meromyza, Fitch, Riley. The Wheat-Stem Maggot, Lintner, 
(Plate I, Figs. 1—8. 
[A slender green, or greenish-white maggot, with two black mouth-hooks, gnawing 
and tearing the tissues of the stalks of wheat and rye, in fall and spring, and again in 
June; the first brood just above the root, and the second immediately above the upper 
joint.| 
INTRCDUCTORY.* 
This insect is probably one of our earliest pioneers, if not an 
aborigine, its work having been noticed in the west at least thirty- 
eicht years ago, when nearly the whole region was a wilderness; 
but it has never been mentioned in the reports of this office, and 
is almost entirely unknown to farmers. This ignorance is largely 
due, no doubt, to the fact that its work in autumn and spring has 
been very commonly mistaken for that of the Hessian fly, to which 
it bears a considerable resemblance; while its midsummer injuries 
to grain which has headed out, are similar in general appearance 
and effect to those of the stalk-borer. 
It attacks winter wheat in autumn at the same time as the Hes- 
sian fly, working like that at the base of the stalk, just above the 
root, and producing upon the young plant a precisely similar etfect ; 
while the larva itself is a slender, white, or greenish-white maggot, 
which an unskilled observer would be little likely to distinguish 
from that of the fly in the same stage. On the other hand, its 
presence in a field of heading wheat in summer is betrayed only by 
the apparent premature ripening of here and there a head of the 
grain, which on examination is found to be blighted and worth- 
less,—an injury almost precisely imitated by the stalk-borer, the 
only external difference being that a stalk infested by the latter 
insect shows a smail external opening through which the worm has 
entered, while that bearing the bulb worm is entire. 
It has also been generally ignored by wheat growers, from the 
fact that its injuries are commonly relatively trivial at the season 
when they are conspicuous,—i. e. in midsummer. The blighting of 
one or two per cent. of the heads of a field of wheat is ordinarily 
passed by as insignificant. Lately, however, it has shown a capacity 
for mischief which has brought it to the front as always a danger- 
ous enemy, and sometimes a most destructive one, certain fields of 
* For asummary of this article, see p. 28. 
