Article beginning on page 3.
Psyche 3:3-6, 1880.

Full text (searchable PDF)
Durable link: http://psyche.entclub.org/3/3-003.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.
EXPERIMENTS UPON THE EFFECT OF COLD APPLIED TO CHRYS- ALIDS OF BUTTERFLIES.
1. In May 1878, I placed many chrys-
alids of Papilio ujax, from eggs laid by form walshii, in the ice box. The youngest were aged but 10 to 15 minutes after pu- pation and were dl1 soft ; others were add- ed at intervals up to the age of 24 hours (the chrysalis is hard at about 12 hours), and others yet at 2 days, 3 days and so
on to 8 days after pupation. All were re- moved from the box on the same day. The
exposure had been from 19 to 5 days, those chrysalids which were put in latest gener- ally having had the shortest exposure. I wished to determine, if possible, whether, in order to effect any change, it was neces- sary that cold should be applied immediate- ly after pupation, or if one or several clays might intervene between pupation and ic- ing. Inasmuch as no color begins to show itself in the pupa till a few hours, or at most a day or two, before the butterfly
emerges, I thought it possible that cold applied shortly before that time might be quite as effective as if applied earlier, and particularly very soon after pupation. The result was that more than half the young- est and immature chrysalids died ; one
which had been exposed at 10 minutes
after pupation, two at 1 hour, one at 2
hours, two at 8 hours. On the other hand, one exposed at 15 minutes, one at 2 hours, and one at 12 hours, produced butterflies. The ten~perature was from 32O to 34O F.
[0å to lo C.] most of the time, rising some- what daily as the ice melted. The nor-
mal chrysalis period in this species is from 11 to 14 days, in case the butterfly emerges the same season, but now arid then a single butterfly will emerge several weeks after pupation. The latter is an uncommon oc-
currence, however, as usually the chrysa- lids which do not give images within 14
days retain them till the following spring. The form which would naturally emerge
the first season from these chrysalids is mum4us, but all the overwintering chrys- alids would produce telamonides or walshii, which latter are the winter forms of the species. If then, from the chrysalids sub- jected to cold, the winter form should
emerge the same season, it would be owing to the exposure to cold.
On the 14th day after taking the chrysa- lids from the ice, one telamonides emerged, from a chrysalis placed in tlie ice box 3 days after pupation, and kept there 16 days.



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

PSYCHE.
On the 19th day, emerged one ielamo11ides, emerged 4 q at 8& to 94 &J's after
or a form between that wid walshii, from a removal from the ice, and 5 are nowliving chrysalis put in the box 12 hours after pu- and will pass the winter.
From lot KO. 2,
pation and kept there 11 days.
On the emerged 1 ^ 5 9,atS fo 9days; another 19th day emerged one waishii, from chrys- 9 came out at 40 days, and 5 go over the alis 2 hours old, and on ice 11 days. All winter. From lot No. 3, emerged 4 t at the rest emerged unchanged marcellus, but 9 to 12 days ; another ^ at 54 days, and at periods prolonged in a surprising way : - 6 were found to be dead. One on 43d day, exposed at 15 minutea.
this experiment, I wished to see, as
One on 46th day, exposed at 2 hours,
exactly as possible : 1% in what points
One on 53d day, exposed at 24 hours.
changes would occur; 2d, if there would
One on 62d day, exposed at 6 days.
be any change in the shape of the wings, One on 63d day, exposed at. 4 days.
as well aa in markings and coloration, - One on 66th day, exposed at 7 days,
that is, whether ths shape might remain
One on 77th day, exposed at 4 days.
that of marcelhts, while the markings might One on Slat day, exposed at 12 hours,
be of te!amonides or ~~l~hii, or a summer One on
day, exposed at 5 days,
form with winter markings- (in previous
One on 96th day, exposed at 19 hours,
experiments I had not noted this point 60 Five chrys&& lived. over until the
carefally as I wished now to do) ; 3d, to spring of 1879, when all produced t&- ascertain more. closely than I had yet done 'manid+
what length of exposure to cold was re-
quired to bring about a decided change,
2.
In June 1879, I obtained eggs of and what would be the effect of prolonging the form marce~, and in due time had
that period. After my experiments with
from them 104 cllr~salifi~.
I placed about miodes thaws, as shown in Butterflies one third, or 35, in the ice box, at from 12 of N. A,, v. 2, and which had resulted in 24 hours after pupation, dividing them a suffnaion of color, I hoped that I might see into three lots : lst, 9 chrysalids, kept on a similar change in Papm *, brought ice 14 days ; 2nd~ 12 chrysalids, 20 days ; about either by the low temperature or pro- ad, 11 chrysalids, 25 days. Temperature longed exposure. and conditions the same as in experiment I obtained from these chrysalide 11 pep No. 1. feet butterflies, 1 % 10 9. Some others Of the 69 chrysalids not exposed to cold, emerged crippled, and these I rejected, as 84 gave butterflies at from 11 to 14 days it was not possible to make out their mark- after pupation, and one additional example ings satisfactorily. From lot No. 1, 14 emerged 11 Aug., or at least 2-2 days past days : 1 9 between ~~arcdlus and tala- the regular period. I reserved these chrys- -ides, 2 ? ma'ivellus. These latter that I might be able to compare the were pale colored, the light parts a dirty butterflies from these with the butterflies white, the aubniarginal lunules on. hind from the same lot of eggs, but whose chibys- wing only two in number and small, at alida were iced.
anal angle one large and one small red
Of the chrysalids on ice, from lot NO. 1, spot, and the frontal hairs very short.



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

PSYCHE. 5
The black of 'the first, or intermediate, female was also pale, but the tight parts were more green and less sordid ; there
were three large lunules, the anal red spot was double and connected as in telaaoni- des, the frontal hairs were short as in
welhs. I find these the most salient
points for comparing the several forms of P. ajax. la nature there is much difference in shape also between rfwrcellus and teh- monide% stilt mote between rnarcdius and walskii, and the latter may be distinguished readily from telantonides by the white tips of the black tails. In telamnides the
white edges both sides of the tail, Walshii is smaller and the anal spot is larger and edged with white on upper side, and the
frontal hairs are long and brush-like and black. In marcellus they are very short
and with much yellow ; in telamonides
they are of a length between the othertwo, black with yellow next the eyes.
From lot No. 2, 20 days, came : 1 9
mu~cellus, with single red spot; 1 9
between 1narceKus and telmnides, the
colors pale, the lunulea all obsolescent, two large red spots but not connected, frontal hairs of medium length, as in tehonides; 1 9 between marcetlus and telurnmiides,
color not pale, but black and green, three lunules, two large red spots, frontal hairs short; 1 9 telamonides, colors black and green, four lunulea, a large double and
connected red spot, frontal hairs medium ; 2 ? tdtowmt'ries, colors like last, three aud four hinulea, two large red spots, no: connected, frontal hairs medium.
From lot KO 3, 25 days : 1 TY tela~lo~f
ides, clear colors, four Iwge Iimules, one large and one small red spot, frontal hairs loag; 1 Q t?lammides, of medium color,
four lunnlee, large double and connected red spot, frontal hairs long.
In general shape all are marceilus, the
wings produced, the tails long.
By which it appears that those exposed
25 days were fully changed ; of those ex- posed 20 days, three were fully, two partly changed, and one not at all. Of those ex- posed 14 days, one partly, two not at all. The butterflies from this lot of 104
chrysalids, but which were not subjected to cold, were put in papers as they emerged. Taking 6 % 6 $ from the papers, as they
came to hand, I spread them and compared with the iced examples.
Of the 6 %, 4 have one red anal spot
only, 2 have one large and one small; 4
have two green submarginal liinules on
hind wing, 2 have three, and these latter have a fourth, which is obsolescent, at outer angle ; ail have short frontal hairs.
Of the 6 ?, 5 have but ona red spot, I
has one large and one small spot ; 5 have two Innulea only, 1 has three; all have
short frontal hairs.
Comparing 6 of the females from the
iced chrysalids, being those in which a de- cided change occurred, with the 6 females not iced : -
1.
All the former have the colors more
intense, the black blacker, the light, green, 2. In 5 of the former the greenlunulea
on hied wings are decidedly larger; 3 of the 6 have four distinct lunules, 1 has three, 1 has three, and a fourth, at outer angle, obsolescent.
Of the 6 sot iced, none have four, 2
have two, and a third, being the lowest of the row, obsolescent, 3 have three, the
lowest being very small, 1 has three and a fourth, at outer angle, obsolescent.




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

3. In all the former the subapical spot
3. The former has a large double con-
OB fore wing and the stripe on same wing nected red anal pot, edged with white ; 3 which crosses cell inside the common black of the latter have but one red spot, 2 have band, are distinct and green;
in all the one large and one small spot, 1 has one latter theae marks are either obscure or large red spot and a red dot. obsolescent. 4. The former has the subapical spot 4.
In 4 of the former there is a large and stripe in cell clear green ; 1 of the lat- double and connected red spot at anal ter has the same, 5 have these obscure or angle, and in 1 of them it is edged on its obsolescent. - upper side by white ; 2 have one large and Looking over all, of both sexes, in both one small red spot. Of the latter, 5 have lots, the iced and not iced, the largeness of one spot only, and the 6th has one pot the green eubmarginal lunules on fore and a red dot.
wings in the iced examples is conspicuous 5.
The former have all the black por- as compared with all the others, - though tioss of the wing of deeper color but of less this feature is included inthe general wid- extent- the bands being narrower ; -on ening of the green bands spoken of. the other hand, the green bands are wider In all my experiments at any time made
as well as deeper and
clearer colored, with P. ajm, if any change at all has been Measuring
the width of the outermost produced by cold, it is seen in the enlarg- common green band along middle of upper ing or doubling of the red anal spot, and median interspace on fore wing in tenths of in the increased number of clear green a millimetre, I find it as follows : -
lunules on hind wings. Almost always the On iced chrysalids, 81,66,76,76,66,66. frontal hairs are lengthened, the color of On not iced, 56, 56, 51, 51, 46, 51. the wings deepened. So also the extent of Measuring the common black disca-1 the black area is diminished. All these band along middle of lower median inter- changes are in the direction of telamc- space on same wing : -
nides, or the winter form.
On the iced, 51, 66, 51, 51, 56, 61.
That the effect of cold is not simply to On the not iced, 76, 71, 66, 63,71, 76. precipitate the emerging of the winter In other words, the natural examplea
form, making the butterfly which would
are more melanic than the others,
naturally leave its chrysalis in the succeed- I find no difference in length of tails or ing spring to emerge in the season in in the length and breadth of the wings. which it fed as a caterpillar, is evident The cold has produced no effect in the from the fact that the shape is always that shape of the wicga.
of the summer form, while the markings
Comparing 1 male from the iced chrys- are of the winter form. Those chrysalids dide with the 6 males not iced 2 -
which go over the winter, on the other
1.
The former is bright colored ; 2 of hand, do not have the summer form, but the latter are the same, 4 have the black the winter, and the markings agreeing -
pale, the light pale and sordid.
thereto, just as in examples in nature.
2. The former has four hroules ; 8 of On these the cold haa produced no effect the latter have three, 8 have two only. whatever. (To fee wdinued onp. 15,)



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