206 
MEMOIES OF TDE ifATlONAL ACADEMY OF SCIE^^TCES. 
^‘Tlie cocoon is a rather close, line silken one, and transparent when the outer ijrotecting 
material is removed. ThivS last may he either a leaf, folded or otherwise, excrement, or other 
matter which the larva entangles in the loose outer web of the cocoon for concealment and 
protection.’^ (Kiley MS.) 
Pupa . — Like that of 8, Ipomew^ but slightly sliorter, and the spine of the cremaster a little 
more acute. Hinder edge of thorax, with a transverse series of nine square black tubercles; 
surface slightly punctured, especially on the front edge of abdominal segments 5-7, the last thi^ee 
segments smooth, tip rather blunt. Cremaster small, the two spines short and stout, granulated 
and corrugated on the surface. Length, 20 mm. (From IT. S. Ts^at. Mus.) 
This is our commonest Schizura, and occurs on the willow and thorn late in August in Maine. 
August 28 one had spun a slight cocoon. 
‘^Length varying from 12 to 21 mm.; color rich shiny brown. In general characters, and 
especially in the row of eight blunt, tooth-like, dull, black inojections from the posterior dorsal 
margin of the mesothorax, it resembles closely the pupie of the two other species of this genus 
which have this stage described, viz, 8. leptinoides and *S'. ipomew. From these species it may be 
distinguished, however, by the character of the two prongs to the cremaster. These are much 
shorter than those of ipomew (which are three times as long as wide), being scarcely longer than 
the width, and the inner branches or teeth are short, and the small inner basal teeth are absent 
or nearly so. 8. leptinoides is readily separated bj’’ the fact that the branches in this species are 
themselves brand led or bitoothed. 
“About four days are required for ]>upation from the spinning up of the larva. At first the 
color markings of the larva are retained with considerable distinctness in the pupa, but these are 
soon lost and the normal brown color assumed.^’ (Edcy MS.) 
llahits . — Tlie caterpillar of this moth, more commonlj'’ met 
with on the apple tree, we have found September G on the elm at 
Brunswick, Me. At about this date, Harris says, it makes its 
cocoon, which is thin and almost transparent, resembling parch- 
ment in texture, and covered generally Avith bits of leaves on the 
outside. The caterpillars remain in their cocoons a long time pre- 
vious to changing to chiysalids, and the moth appears the follow- 
ing May and June. 
Tliis and the other species of the genus aredoubtless protected 
from the attacks of birds by their close resemblance to a dead, 
dry portion or blotch on the edge of the leaf, as they usually feed 
on the edge. 
Miss Emma Payne was the first to call attention to its mimicry of leaves partly dead. We 
quote her interesting account: 
1 think this worm furnishes a wonderful iustaiico of mimicry of the vegetable by the animal organism. The 
green segments just back of the head resomhle a small portion of the green leaf, and the other x^^irts admirably 
counterfeit the brown and russet tints of the dead leaf, while the form of the animal in its various x)osture8 aids the 
deception by its resemblauce to a leaf partly alive and x)artly dead, the green mostly eaten and the brown torn. 
(Amer. Ent., ii, p. 311.) 
I have noticed that this caterpillar feeds very conspicuously, but is imotected by its resemblance 
to the twisted, partly dead ends of some of the leaves, the oblique markiugs of the larva resembling 
the twisted dead and russet portions of the leaf. 
The following observations have been made by Professor Eiley: 
“The larva of the above species is found feeding on quite a number of diftereut plants, such as 
oak, elm, plum, apple, dogwood, alder, wiuterberry, rose, and blackbeVry, also on hickory. 
“The insect is evidently two brooded, those of the first brood spiuning np at the commence- 
ment of July, while larvm of a secoud brood, often only about one-fourth grown, are found as late 
as October 10. 
“The cocoon is very thin and looks much like parchment. It frequently draws a few leaves 
together for this purpose, and changes to a chrysalis in about four days, which is at first of the 
same color as was the caterx)illar, the green segments being distinctly visible, but soon changes to 
J’ig. 79.— Pupa of Sehizura unicornis. 
