17. 
There is but one other insect known to attack the “bulb” of wheat 
after the method of this maggot, and that is the Hessian fly, and I 
have thought it especially desirable to give our species a name 
which shall serve to distinguish it from the latter, with which it has 
been so generally confounded. 
DESCRIPTION. 
Differential Characters. The insects with which this species is 
most likely to be confounded in the larval stage are the Hessian 
fly in fall and spring, and the stalk-borer and the straw-worm in 
midsummer. 
As compared with the larva of the Hessian fly in autumn, the most 
useful distinguishing character of the bulb-worm is the presence of 
the two slender, black hooks beneath the head, with the tips curved 
downwards and not towards each other, and which are kept in 
almost constant motion, backwards and forwards. (Plate I, Fig. 4.) 
These are easily seen with a little attention, in both dead and living 
larve. The Hessian fly larva (Plate XV), on the other hand, has 
no mouth organs whatever, the mouth being reduced to a mere 
opening on the surface. During the winter and spring, until about 
the first of May, the discrimination of these species is easy, since the 
“fly” is at this time in the ‘‘flaxseed” state, the living larva being 
enclosed in a tough brown case, about the size and shape of a flax- 
seed, while the bulk worm is a naked, greenish-white maggot. Irom 
this, again, the second brood of the larva of the Hessian fly may 
be distinguished, like the autumnal brood, by the absence of the 
mouth- hooks, as well as by the exact character of the injury to the 
wheat. The larva of the ‘‘fly” does not penetrate the stalk, like the 
bulb worm, but lies imbedded between that and the inner leaves. 
In this latter particular our larva resembles the wheat-straw worm 
(Isosoma tritict) (Plate II, Fig. 3, a and b), which also penetrates 
the stalk; but from this the spring brood of the bulb worm may be 
told by the fact that the straw worm has a distinct head very different 
from the first segment of the body, and armed with bilateral jaws 
(Fig. 3, d), while the head of the bulb worm is merely the pointed 
anterior end of the body, and has only the longitudinal hooks before 
mentioned. The straw worm also infests the upper part of the 
stem but rarely, usually occurring two or three joints below the 
uppermost, while the second brood of Meromyza is almost strictly 
confined to the stem just above the upper internode. 
While the work of the latter has a superficial resemblance to that 
of the stalk-borer, the insects themselves are not at all alike, the 
latter being a small, striped caterpillar (Plate XI, Fig. 4,) with 
jointed legs and with prolegs; and the injuries are likewise readily 
distinguishable by the fact that the stalk-borer makes a round hole 
from the outside, usually at the internode, through which it enters 
the cavity of the stalk. 
Imago. (Plate I, Figs.1 and 2.) About .18 inch long by .8 inch 
wide, pale yellowish-green; head (fig. 2) produced in front of the 
eyes, broadly rounded anteriorly, marked above with delicate longi- 
tudinal striw; a triangular black spot on the occiput, including the 
