Notes on the Early Stages of Two Sphingidae
International Journal of
BY ALPHEUS SPRING PACKARD
PROVIDENCE
R. I.
It is evident that what little we know, notwithstanding all the effort which has been lnade, of the life-histories of our spligidae, will have to be done over again in a more thorough and systematic way, while each stage should be very fully and comparatively described, in order to ascertain the probable relative age both of the species of the genus, and of the genera themselves. In this way we shall be able to arrive at a probable phylogeny of the sphingid family; i.e., we may discover the ancestral forms, i.e., those which have through adaptation survived many ages, and the later, more highly modified species, which are the result of adaptation to newer, changed conditions. One may feel sure that in this attractive labor, he will derive great intellectual benefit and stimulus. It will not only cultivate his powers of observation, but add to habits of reflection, and draw out whatever latent philosophical capacities or tastes may have laid dormant in his nature. In sucl work Weismann's beautiful 'Studies in the Theory of Descent" will be the student's guide, and it is greatly to be desired that our younger lepidopterists should obtain that work and make a careful study of it. From our limited experience in rearing only two or three sphingids, and a number of bombyces, we feel confident that the facts and theories in that stimulating work are as a rule well founded; and
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EARLY STAGES OF TWO SPHINGIDAE.
we are glad to acknowledge our great
indebtedness to the learned and
thoughtful author. 2ks the work is well
translated by Prof. Meldola, and can be h,’d
at a very moderate price, far less than
the original cost, there is little excuse
for not buying it.
Thus far we have perhaps not a
single thorough and well illustrated
lifehistory of any of this group, and we are
still in much the same condition that
they were in Europe, before the
publication of Weismann’s work. This is
not written to depreciate in any way the
excellent and honest work which has
been done by Messrs. Lintner, Riley,
ttulst and others. What we mean to
say is that the life-histories thus far
published, have not been worked out
with reference to the origin of the
markings, the lines, stripes and spots;
nor with reference to the probable
relative ages of the species, nor to the
position in nature of the different
genera, so as to enable us to determine
which are the older or simpler forms,
and which the more recent, more
modified genera, or species. The work can
hardly be done by one person, or in
even several seasons, but should a few
co6perate, a great deal of desirable work
could be in the course of a few years
performed.
The few notes below were made
during the past summer on two forms allied
to those interesting genera Deilepila
and Thyreus, as well as Philampelus
and Chaerocan@a. I had no intention
of doing any work in this family, and
the notes are not intended to be at all
final, but imperfect as they are, they
show how interesting it would be to
know something ofthe early larval stages
of the American species of Amibhioz,
Thyreus, Enyo, Deilephila, Philam.
2belus, and certain tropical forms, to
which the genera in question are allied.
LQ’e-history of Deidamia
inscr@
turn. (I-farris.
Mr. James Angus, of West Farm,
N. Y. had the goodness to send me the
eggs of this sphingid, which is allied
to Thyreus abbotii, and I was able to
carry it through its stages, while in
Brunswick, Maine. As the climate is
much cooler there than in New York,
the nights especially being much lower in
temperature, the length of the different
stages will probably be found to be much
greater than in New York, The larva,
according to Mr. H. Edwards’s very
useful Bibliographical catalogue of the
described transformations of North
Anerican lepidoptera, has been briefly
described by Strecker (Rhopal. et
Heteroc. ) and by Fernald (Sphingidae
New England, 7o,) but the early stages
have not yet been described. The
description of the larva in Strecker’s work
was however given him by Mr. John
Akhurst, from memory, and Prof.
Fernald’s description is simply copied
from Strecker. According to/kkhurstthe
larva is ’full-grown about the last of
June or beginning of July, and is
singlebrooded, the perfect insect appearing
about the middle of May. Several
moths issued in Providence the end of
May and early in June from pupae
kindly given me by Mr. Angus, but
though several males and females were
placed within the mating bag no
fertilized eggs were obtained. The
eggs froin which my larvae were bred
were received from Mr. Angus, 24
June 890.
’gg.--Rounded oval, rounded alike at
each end, somewhat longer than broad,
length 2 ram. greenish in color. The
shell is thin, smooth when examined
under a Tolles triplet of high power,
and also under a } inch Tolles objective,
but with the latter, scattered roughnesses
are perceivable, though not forming
true granulations.
Stage Z..lust hatched on the
morning of 7 (...truncated)