322 
most nearly, forming a tunnel of thick, dingy web between the two. 
In entering a second acorn it not infrequently intrudes upon a Balani- 
nus larva, in which case the latter is literally, as well as figuratively, 
‘‘forced to the wall.” While the caterpillar appropriates to itself all 
of the remaining provision within the shell, it does not, to the best of 
my knowledge, include the Cureculio larva in its feast, as I have fre- 
quently found the latter blackened and shrunken on one side of the 
coarse, dry, granular castings of the Lepidopter, which are but very 
sligntly webbed. In emerging, when full grown, the larva almost in- 
variably cuts its ragged-edged exit through the involucre as well as 
the shell of the nut, which Balaninus rarely, if ever, does. It then 
drops or spins down to the earth, where it forms for itself, against the 
base of the tree, a slight cocoon, outwardly disguised with bits of bark; 
or it constructs a nest, flattened, broad-oblong case from the contigu- 
ous surfaces of two leaves or of a folded leaf, almost, but seldom quite, 
severing the margin from the leaves. This case is firmly joined at the 
edges and slightly lined with silk, and within it the larva remains un- 
changed for from seven to nine months, transforming to pupa only 
about ten days before the moth appears. This protracted larval dor- 
mancy makes it a somewhat difficult insect to rear, as it must not be 
kept too dry nor have a superabundance of moisture. The pupa is of 
a golden-brown color with distinct dorsal sculpturing and spiny ridges, 
and upon giving forth the moth is protruded more than half way out 
ot the case. 
The perfect insect, which varies in wing expanse from 15 to 24™™, is elegant in 
coloring, with an intermixture of dull red and grayish brown or cream colored 
scales—the lighter color predominating in some specimens, while the darker does in 
others. The especial ornamentation consists in three more or less interrupted coppery 
or bronzy metallic fasciz ; in an indistinct pattern of black streaks and dots near 
the outer margin of the primaries, and in the heavy, pale-gray fringe succeeding a 
narrow red marginal line. The under sides of the wings of both sexes have, in some 
lights, a peculiar metallic green shade. The male is usually one-third smaller than 
the female, and is most characteristic with his profusely tufted hind legs and feet. 
The hind-wings are very fragile and at the same time difficult to extend, so that 
it is by no means an easy task to set the insect without injury to its beauty. 
From this species I have bred in small numbers two species of para- 
sites, a Cymodusa sp.? and a small Tachinid, which, Dr. Riley informs 
me, is new to the collection of the National Museum. 
CYNIPID GALLS IN ACORN. 
In opening acorns of Q. tinctoria I have found from five to seven per 
cent infested by Cynipid larve of a species to which Dr. Riley, who has 
been familiar with them for many years, has given the MS. name Cal- 
lirhytis fruticola. This tiny Hymenopteron converts the cotyledons of 
the fruit into a mass of small, white, oval cells, the walls of which are 
excessively hard. From twelve to twenty of these cells are often found 
