Article beginning on page 63.
Psyche 5:63-66, 1888.

Full text (searchable PDF)
Durable link: http://psyche.entclub.org/5/5-063.html

The following unprocessed text is extracted from the PDF file, and is likely to be both incomplete and full of errors. Please consult the PDF file for the complete article.

PSYCHE.
THE NATURAL HISTORY OF ANOSIA PLExIPPUS IN NEW ENGLAND.
BY SAMUEL HUBBARD SCUDDER, CAMBRIDGE, MASS. This butterfly passes the winter in
the imago state. 111 soutl~ern latitudes, according to Edwards, who has given
it closest attention, it appears early in the spring and lays eggs upon the milk-
weed just out of the ground, beginnkg
in West Virginia in the early part of
May. The insect matures there very
rapidly, and passes through several
generations, according to LMr. Edwards
at least three, and probably four, in
the course of the season, the latest
brood of the butterflies hibernating.
Riley, who was the first to give a toler- ably full life history of the insect,
claimed that in Missouri it was double-
brooded, the broods appearing in the
latter half of June and in October. In
New England, however, what we can
learn of the butterfly indicates a some- what different history. Some years
ago, in p~~blishing an account of its
history here, I claimed that the insect
was only single-brooded, first coming
out of hibernation at the end of June
and early in July, laying eggs for a
month or so, and the butterflies from
these eggs hibernating. A great many
points concerning its history both here
and elsewhere have been brought out
since then, and the facis as we know
them at present may probably be in-
terpreted somewhat in this way.
The butterflies, which are far nmi-e
numerous in the late autumn than at
any other time, seek winter quarters to
hibernate, but with very rare excep-
tions, north of the natural division line of the Canadian and Alleghanian fau-
nas, and even to :I considerable distance to the south of this, possibly sometimes throughoi~t the entire district of New
England, every single specimen per-
ishes. Now and then an old and bat-
tered female may be found in the month
of May, but we have actually on record
as far as I can discover b ~ ~ t two or three instances of this, and one of these is not specific, A female much worn and
faded was found May 12 at Amherst by
Professor Parker? and in another year
the b~tterfly was fo~~nd by Mr. W. D.
Marsh on May 15 and May 21 at the
same place ; while Mr. Caulfield speaks
in general terms of the appearance of
butterflies in Montreal in May. In the




================================================================================

[June 1888-
extreme so~ithern portions of New Eng-
land and tlie neighboring districts, we
have not infrequent appearances of
hibernating butterflies early in May.
But neither hibernators nor their pro-
geny, in the preparatory stages - the
only absolutely certain proof of an early brood, - are with possibly rare excep-
tions to be found in the nostliern half
01- more of New England either in
May or early in June. The first occur-
rence of the insect there in any forin is much lates in the season, generally by
the middle of June, occasionally by the
very first, son~eti~nes not until the very end of this month, when fine fresh but-
terflies make their appearance, at about the same time as, or a trifle later than, the advent a little further ~0~1th of the first fresh brood of butterflies from eggs of the same season,-tli~~s giving all the appearance tl~ro~~gl~o~~ t New England
of an idei~tical swarm of butterflies,
varying in time from those found next
the so~ithern borders of New England
only so much as would be expected
fson~ latitude.
This brood is in my opinion to be
accounted for only on the supposition
that they are coZofiists from the south
which have flown to more northern
Jistricts from that impulse to wander
which is one of' the psychologi-
cal characteristics of tl& butterfiy.
This hypothesis is further supported by
the essentially tropical nat~~re of the
butterfly, which wo~ilcl prevent its es- tablishing itself as a permanent resident rather thn as an annual visitor of
northern districts ; by its well-lcnown
vast pom7ef of flight ; as well as by its comparative history in the south.
These butterflies begin in New Eng-
land to lay their eggs ~isually in the
first week in J~lly, but occasionalIy as early as the mid({le of J~i'ne. Dr. Har- ris records some caterpillars found on
tlie 28th of June which had reached the
length of an inch on the 5th of July,
and I have fo~~nd thein in Shirley,
Mass., of the length of six ~nillimetres, therefore probably in the second stage,
on the 2x1 of June. These wese unu-
sually easly caterpillars of the b1.00i1 wliic11 had flown from the ~0~1th and
wl~icll sometimes makes its advent
early in June. Both Mr. F. H. Sprag~~e
and myself have fo~~llcl them about
Boston as early as the zd of this
montli in good condition, and single
aclditionid specimens were fo~~nd in the same year by Mr. Sprague on the 9th
and 15th of Jii~e. They never, how-
ever, become at dl abundant hefore the
first week in July, when the eggs are
ordinarily laid. The eggs continue to
be laid tliro~gl~o~it this entire month
without any interruption.
As regards the later history of this
butterfly in the north, we are still
somewhat in doubt. Mr. Edwards
urges with great pertinacity that the
behavior of the butterfly in the north is altogether parallel to its behavior in the sout11, but this wo~ild hardly seem as
yet to be settled; at any rate the ap-
pearance of the latest fresh butterflies of the season may easily be accounted




================================================================================

June 1888.1
PSYCHE.
for on the supposition that they were
produced from eggs laid by the older
females of tlie first brood of colonists. For the observer will notice that eggs
are laid by butterflies both in a fairly fresh condition and also by those vvl~icl~ have been upon the wing a long time,
and the closest observations I have been able to give through many summers
both of butterflies seen in the act of
depositing their eggs and of the con-
tents of the ovaries of others, lead me
strongly to the conviction that this but- terfly requires more than a .brief time
for oviposition, the eggs maturing by
degrees and not being fully laid until
tile butterfly has been upon the wing
about an entire mont11. The examina-
tion of butterflies fresh from the c11ry.s- alis shows that the eggs are never
entirely matiwe at this time, while on
the other hand these butterflies retain
their freshness of appearance for a
longer time than usual after they have
come from the chrysalis. That there
is easily time for a second brood of but- terflies from eggs laid by the progeny
of the first colonists (basing our judg- ment ~lpon the facts as given us by Mr.
Edwards in the south), there can be
little doi~bt, but the proof of such a
second brood has yet to be given.
While, thesefore, I an1 compelled by the facts that have been advanced since my
former account of this species was
pubIis11ed to modify my views in one re- spect, I am still inclined to think it in the main correct, viz., that this butterfly is normally single broodecl througho~t
the larger part of New England ; but
that it req~~ires an annual visitation of colonists from the south to exist at all? tlie llihei-nating butterflies perishing ann~~ally, almost to an individual.
Mr. Edwards entertains a different
opinion regarding its life history in
New England and does not believe that
the butterflies which have hibernated
perish to any such extent as 1 have pse- su~ned ; and, becai-~se single instances of hibernating butterflies have been
found in Massacl~usetts, he considers
that "this settles the matter." But he
fails to mention the fact that during the year 1887 when one observer found two
of these hibernating butterflies ill May at Amlierst, this observer (Mr. Marsh),
who was constantly
on the watch for
this butterfly, discovered but these two specimens in the season, while a num-
ber of Mr. Edwards' New England cor-
respondents, whom he had simi1a1-ly
put upon a special search, were unable
to find any; nor does he take note of
the fact that Amherst, the only place in which these hibernating butterflies have yet been found in so northern a latitilde as Massacli~isetts, is in the Connecticut valley, where the isotherms trend north- ward ; and which is but a comparatively
short distance north of those parts of
southern Connecticut, in the valley of
the same riyer. where it is not i~nproba- ble that successfully hibernating butter- flies may be found in all favosable
years; nor is he perhaps aware that the
valley of this river is one in which
southern butterflies find their way far-



================================================================================

ther north than at any other pint in
New England excepting in some in-
stances along the sea-board.
My own collecting in hTew England,
where this butterfly is ~n~~ch less common than further south, leads me to believe
that it is far ei~sier to obtain it by seasc11 for the caterpillar on the leaves of As&- $ias than by capture upon the wing;
and I sl~ould rather decide 11~011 the
presence of buttesflies in any particular district by a search for plants of As-
clejias in suitable spots, than by watch- ing for the butterflies ; so that the fail- ure year after year to find st~cll larvae on yo~~ng a11d tender plants in the very spots which are invariab1y chosen by the July butterflies whereon to deposit their eggs is to me very strong proof that the biittertly does not ordinarily exist in any form
during the early montl~s of the
yeas in regions that I have searcl~ed.
Regarding the later broods it may be
added that the observations of Mr.
Marsh, who I-aised butterflies as late as the latter half of October and even in
November, were made in part at least
upon hotlsed larvae and that at this late epoch of the year the transformatio~~s of the insect are very much slower than
they are earlier in the season.
Thus
Mr. Marsh himself states that the pupal
period in Octoher is aboilt three weeks, while in September it is only about a
fortt~ight. In n~ids~~mtner it is about
ten days.
Mr. Edwarcls, accepting a s~~ggestion
of Mr. Marsh, further ui-ges that the
failure to discover the hibernators in
the spring is di~e to their rarity in the autumn and the latter from the fact that in New England the fields are often
mowed for a second crop and that with
the hay great quantities of milk-weed
are cut down. But aside from the fact
that the larger p.art of the milk-weeds
inhabited by the caterpillass is found
by the side of soads and lanes and
in close vicinity to shrubhery, where
it is not disturbed by the scythe, there is a single fact wl~icl~ seniless this alp- ment absolutely tlseless, viz., that the imago is far Inox ab~~ndant 1;ite in the season t11a11 at any other time in the
year, sometimes swarnling to an exces-
sive extent and found in New England
in the smxe abi~ndance that it is so often fo~~nd in the west. Yet so far as I have been able to find from inq~~iries (~~nfor- tunately not made at the time), in no
instance have hibernators been seen in
yeass immediately succeeding autumns
which have witnessed a vast profusiot~
of butterflies, nor have a~~tnmns of
great abundance been fol1owecl by
spsings of plenty.




================================================================================