STATE AGRICULTURAL SOCIETY. 
833 
LOCCST. LEAVES AND TWIGGS. 
when full grown ; the pupa wintering in a slight cocoon coated outside 
with shreds of dead leaves; the middle of the following June giving out a 
dark hrown butterfly with a yellow glossy band on the middle of its 
fore wings and a broad silvery white one narrowing outwardly, across the 
middle of the hind ones on their under side, its width 2.00. See Harris’s 
Treatise, p. 243. 
331. Black locust midge, Cecidomyia Pscudacacice, new species. (Diptera. Tipulidie.) 
In July and August, the tender young leafets near the tip of the stem 
folded together like a little pod, the cavity inside containing from one to 
three small milk-white maggots, which descend below the surface of the 
ground, remaining there in their pupa state about ten days, and then hatch 
a small blackish midge, the base of its thorax tawny yellow, its abdo¬ 
men pale yellowish with the tip dusky and clothed with fine hairs as is the 
neck also, its legs black with the thighs pale except at their tips, its wings 
dusky, feebly hyaline, with the fringe short, its antennae with thirteen 
short cylindrical joints separated by short pedicels, its length 0.065 to the 
tip of the body in the females, which is the sex now described. - 
Before the small young leafets, which put forth along the opposite sides 
of the main leaf stalks at their tips, become expanded, they are closed 
together like two leaves of a book ; and it is probably at this time that the 
female midge inserts her eggs in the cleft between them, the irritation from 
which and from the small maggots which hatch from them, keeps the leafet 
permanently closed, a slight cavity forming within, in which the worms 
reside, the leafet hereby coming to resemble in its shape a small bivalve 
shell, of the genus Chtinta, the margin being usually more or less wavy. 
The surface remains unchanged outside, but within it assumes a pale greenish 
yellow color. The larva; are milk-white and somewhat glossy, with a light 
green cloud along the middle of their bodies from alimentary matter inter¬ 
nally in the viscera. When menaced with danger, they have the faculty of 
throwing themselves away with a sudden skip, the same as the larvae of the 
Wheat midge. The attachment of the leafets to the stalk becomes so 
weakened when infested by these worms, that I presume they are generally 
broken off by the wind and the worms are thus carried to the ground, 
instead of crawling down the stalks by night as is the habit of the Wheat 
midge. 
I notice these pod-like leafets every summer, upon the locusts in my yard, 
as well as the deformity produced by the following species; but neither of 
these insects have ever been so numerous as to injure the trees in any sen¬ 
sible degree, in my vicinity. 
333. Yellow locust nidge, Cecidomyia Robinicc, Haldeman. 
In July and August a portion of the edges of the leaves rolled inwards 
on their under sides and thickened, inclosing one or two very small white 
maggots which are varied more or less with orange yellow ; producing a 
[Ag. Trans.J 53 
