180 
MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
Pale gTeeii, subglobose, siigbtlj^ concave at the base, smooth, shining. Length, SO mm. ; 
width, 50 mm. Duration of this stage, thirteen days. Laid in small masses on the underside of 
leaves.’^ (Beutenmliller.) 
For the description of the early stages of this caterpillar I have not full notes drawn up from 
living specimens, but have to depend on alcoholic examples of the diflereut stages and the 
excellent colored sketches of Mr. Bridgham, so that this notice is in part provisional, as we have 
yet to see the eggs, although one of the commonest cateri)illars on the oak. 
Firnt stage^ larva just hatched. — Length, o-G mm. August 24. Just before the first molt the 
body is moderately thick and of a pale yellowish tint; the head is brown,* not deej) amber, as in 
the subsequent stages. Tiie anal legs are decidedly smaller than the other abdominal legs and 
somewhat uplifted, or rather extended horizontally. They ai’e slightly retractile, and pi'obably 
bear a few hooks. The large dorsal hump on the eighth abdominal segment, so characteristic of 
the genus vSymmerista, is already well developed, so that the chief generic characters of the larva 
appear at birth. The hairs are minute, short, sparse, and very slightly thickened at the end, all 
of the same length and arising from minute, inicroscopic warts. The dark dorsal line is only 
faintly indicated; the lateral dark brown line well marked, most distinct on the protlioracic 
segment, interrupted at the sutures, and faded out on the eighth abdominal segment. The large 
hump on this last-named segment is large and high, but scarcely differs in tint from the rest of 
the body, though slightly darker. On each side of the ninth segment is a large black comma- 
shaped spot, the point directed forward and downward, while behind them is a median black dot. 
There is a broad yellowish spiracular lateral bainl; above it a pale, dirty white band, edged above 
by the lateral, or rather subdorsal, black line; the underside of the body, including both the 
thoracic and abdominal legs, is whitish. The anal legs bear about six hooks. 
Second stagey after the first molt. — Length, G-S mm. August 27. The head is still very large 
in proportion to the body. The hump on the eighth abdominal segment is larger, more ])ronoun(;ed, 
and orange-yellow, sometimes red; the head is dull amber. The dorsal line is now distinct, and 
the- subdorsal line is triplicated on the two anterior thoracic segments and duplicated on the 
■ eighth abdominal. Behind the dorsal hump there are two, instead of one, median black dots, one 
placed behind the other, and two black spots are added on the side of the body near the base of 
the anal legs, i. e., two on the ninth and two on the tenth segments. On the pro and mesothoracic 
■segments are two parallel, short, sinuous, blackish red lines. The spiracular band and uTiderside 
■ of the body as in the previous stage, but deei)er straw-yellow. The anal legs have a longitudinal 
reddish stripe ou the outside or are reddish near the tip. The hairs are longer and slenderer than 
before, taper a little, but are docked at the tip, and arise from warts, those on the back arranged 
ill a trapezoid. 
Third stage^ after the second molt. — Length, 20 mm. September G. The general shape of the 
body of the mature larva, with its large, smooth dorsal hump and peculiar shining banded skin, 
is now assumed; the specific characters having apparently now appeared, though we have none 
of the other forms {alhifrons and pacltardri) with which to compare it. The head is still large, 
wider than the body, which does not yet grow smaller toward the head as it does in the fully 
grown larva. The body is now richly and very (ionspicuously banded so that already in this stage 
the caterjiillar becomes a very showy object. How it is regarded by birds and ichneumons remains 
to be observed. The narrow thread-like dorsal line and the lateral line are now inclosed in a 
broad, dull, Avhitish-gray baud bordered on each side by a faint, dark line. There is a subdorsal 
straw-yellow broad band. The spiracular deep straw-yellow band is bordered below by a double 
l)lackish-red broken line. The dorsal humi> is bright coral red, so bright and conspicuous as to 
suggest that when the end of the body is suddenly moved at the presence of an iclineumou the 
movements of the bright red mass may frighten away the unwelcome visitor. The black spots 
and slashes on the ninth and tenth segments have increased in number. The two median 
reddish black dots of the second stage have coalesced and formed a long stripe, flanked on each 
side by a shorter strijje, and an outer dot ou the ninth segment. On each side of the ninth and 
tenth segments are two blackish spots. 
Benteumiiller says ‘‘jet-black, sbiny’^ (p, 75). 
