ON CERTAIN SPECIES OF SATYRUS.

BY W. H. EDWARDS, COALBURGH, W. VA.

1. Nephele.—Kirby, Faun. Bor. Amer., 1837, described this species as follows: “Wings brown; primaries both above and below with a paler submarginal broad band including two eyelets; the upper ones surrounded by a paler atmosphere, with a black iris and white pupil; on the under side the atmosphere of the eyelets is most distinct and forms a kind of glory round them,” etc. Nothing is said of the sex, but apparently this is the description of a female. The wings of the male are blackish-brown, usually of uniform shade throughout—that is, in the typical male, corresponding to the female of Kirby. But there is a frequent departure from this type in the direction of Alope, the “pale atmosphere” about the ocelli appearing in the male, and in both sexes gradually widening and becoming less obscure till it culminates in a clear yellow band. When this is reached we have Alope, Fabr. So that Nephele intergrades completely with Alope. But this is not everywhere and always. The metropolis of the typical Nephele is in Canada and northern New England, that of Alope in the States south of New York. There is a line running about with the southern boundary of New York, or it may be, in Pennsylvania, below which Alope holds sole possession, and no tendency is discoverable towards Nephele. In the extreme northern area, if there is any departure from typical Nephele, it is the exception, not the rule.

Mr. Scudder, in his essay on The Distribution of Insects in New Hampshire, 1874, says of Alope: “This insect is tolerably abundant, sometimes very common, in the southern half of New England. The most northern localities … are Norway, Me., Thornton and Shelburne, N. H., and Sudbury, Vt.” Thornton is just south of the White Mountains, and Shelburne is close by the mountains on the north-east. Of Nephele he says: “It is found over the whole northern half of N. E. in great abundance. The only locality in which I have met with it is in Massachusetts, in the elevated region about Williamstown,” &c. This place is in the north-west corner of the State, next the Vermont line, and the elevated region spoken of is a continuation of the Green Mountains. So it appears that Nephele comes down to the Massachusetts line and Alope flies as far as the White Mountains. In the intervening district the intergrades fly just as in New York.

I made application to Canadian lepidopterists for information about the occurrence of Alope, and soon ascertained by examples sent me that Nephele with a pale atmosphere, but not at all indicative of a band, passed by the name of Alope. Thereupon I sent a typical Alope to Mr. William Murray, of Hamilton, who kindly offered to make inquiry of his acquaintances in different sections of Ontario. He replies, 31st Dec, 1879: “I now send you my information. Of all my correspondents not one has ever seen an Alope that has been taken in Canada, but Nephele has been taken by all. I begin to think that Alope is not to be found in Canada at any point.”

Mr. H. H. Lyman writes from Montreal: “In July, 1876, I spent a couple of days at a farm near Freligsburg. P. Q., one mile north of the Vermont border, and found Nephele very common. Most of the specimens taken showed a yellow ring about the eye-spots on primaries, but one of them shows on upper side a somewhat faint, but quite discernible, patch corresponding to the yellow band of Alope. Was at same place in 1877. Alope was not seen either year.” Mr. Caulfield writes Mr. Lyman: “I have never taken a specimen of Nephele showing any tendency towards Alope, nor have I seen any Canadian examples showing it.” Mr. Lyman adds that at Portland, Maine, where he collected several summers, Alope was common as well as Nephele and all intergrades.

(To the west of New York, in the latitude of the belt spoken of, it is believed that the two forms fly together at least as far as Wisconsin. Prof. A. J. Cook writes that both are common in Michigan, south of the latitude of Grand Rapids. At Toledo, Mr. John Wilson writes that Nephele is rare, and Alope unknown, so far as appears. At Cleveland, O., Dr. J. F. Isom informs me that Alope is very rare, but that Nephele is abundant in some seasons. In south-west Ohio, Dr. H. K. Landis, of Columbus, writes that he cannot learn that either form has ever been taken. They are not mentioned in Mr. Dury’s list of butterflies found about Cincinnati. But in northern Illinois Nephele is abundant and Alope not found at all. So that somewhere between New York and Illinois, in Ohio and Indiana, Alope seems to disappear, while Nephele becomes the sole form; but whether the separation is abrupt or gradual is not ascertained. As the information which I have been able to gather is so meagre as regards the States west of New York. I shall confine my remarks to that State and New England.[1])

We have therefore in these separated districts two apparently good species, answering to any definition of that name. But between, there is a belt of latitude passing through New York and southern New England, where in one section or other both types are found and the whole series of intergrades. In this belt Alope and Nephele are found to be dimorphic forms of one and the same species. I formerly was of the opinion that they were distinct species, though in some districts there were intergrades. I thought these approaches of one to the other did not bridge the whole space between. In a paper printed in Proc. Ent. Soc. Phil, 1866, I gave my reasons therefor. But some observations made in July, 1876, at Martha’s Vineyard, led me to suspect a closer relationship between the two species or forms. In the open country back of Oak Bluffs, I found these butterflies fresh from chrysalis, and in considerable numbers. They were all very black, diminutive, and there was every grade from what I had been in the habit of calling Nephele to unquestionable Alope, with a broad clear-colored band. The band was not yellow, however, as in the typical Alope, but reddish-yellow like that of Pegala, which Fabricius called rufa in distinction from flava, applied to Alope. Mr. Scudder took the same small reddish-banded form on Nantucket, which island is about 30 miles from the mainland, Martha’s Vineyard being about 7. I call this variety Maritima, but whether it is restricted to the islands, or appears on the adjacent coast, I am not yet advised. Mr. Mead obtained for me a large number of eggs of this butterfly, while at the Bluffs shortly after my departure. They were laid by the broad-banded females in confinement and mailed to Coalburgh. There the larvæ hatched out, and these as well as the eggs were found to be precisely like the same stages of Nephele from Catskills. But none of the larvæ survived the winter.

In the belt spoken of, Nephele rather keeps to the highlands. It is the prevailing form in the Catskills, if with it are classed the intergrades, but full-banded Alope may be taken in small numbers every season. Along the Hudson River, Alope is the common form, but I have received intergrades very near to Nephele from Mr. Hulst, taken at Hoboken, N. J.; and a black Nephele ♂ from Mr. H. Laitloff, which he writes me was taken some five years since near Greenville, Jersey City. It was so unusual a form that Mr. Laitloff sent it to me for name. At Coalburgh, W. Va., Nephele is never seen, but Alope is the only form; and so on southward.

2.—Alope was described by Fabricius, Ent. Syst., 1793, as fuscous (fusca) with a yellow (flava) band; with two ocelli on fore wings; on hind wing one ocellus above, six below. The band is very broad in the female, usually narrower in the male, pale yellow in both sexes. The ocelli resemble those of Nephele and vary in same manner. Usually they are round, but sometimes oval; are either small or large, often equal, but sometimes the upper is larger, at others the lower. Now and then a third pupilled ocellus appears, and individuals have been taken with but one ocellus (the upper). It is not very unusual to find examples in which a black point, or what may be considered as a rudimentary ocellus, presents itself. On the upper side of hind wing is often a small but complete ocellus near inner angle, but in many cases it is partly or wholly wanting; and occasionally there are one or two black spots in addition. The males in the majority of examples have six small ocelli on the under side of the hind wings; the females rarely have six, and often none at all. At the north, Alope is blackish-brown, more brown in the female; but to the southward brown prevails in both sexes; and it is of a lighter shade, while the under side has a tint of yellow more or less decided over whole surface, often mixed with gray. The band is of yellow, or with a slight ochrey tint. This is a description of the extreme southern type, and to distinguish I call it var. Texana. All examples from Texas which I have seen have a complete anal ocellus, and six ocelli beneath, of pretty large size—larger than in northern Alope—in distinct ochrey rings; the pupils white points with a few blue scales about them in the larger ocelli. Of 70 Nephele ♂ examined, 50 have 6 ocelli, 11 have 5, 3 have 4, 3 have 3, 2 have 1, 1 has 0.

Of 55 Nephele ♀, 6 have 6, 1 has 5, 4 have 4, 13 have 3, 7 have 2, 13 have 1, 11 have 0.

Of 24 Alope ♂, 15 have 6 ocelli, 3 have 5, 4 have 1, 2 have 0.

Of 25 Alope ♀, 12 have 6, 1 has 4, 4 have 2, 4 have 1, 4 have 0.

Therefore of Nephele ♂, 71 per cent. have 6 ocelli, 4 per cent. have under 3; 1.4 per cent. have 0.

Of Nephele ♀, 11 per cent. have 6, 56 per cent. have under 3, 20 per cent. have 0.

Of Alope ♂, 62 per cent. have 6 ocelli, 25 per cent. under 3, 8 per cent. 0.

Of Alope ♀, 24 per cent. have 6, 48 per cent. have under 3, 16 per cent. have 0.

3.—The dark Satyrus which inhabits Illinois and westward has gone by the name of Nephele, though differing somewhat from Nephele of the east. I was struck by the difference between a series sent me by the late Mr. Walsh from Galena, years ago and when I first began collecting butterflies, and a series of Nephele taken in the Catskills, and I have always kept the two apart in my cases, considering the Illinois form as at least a well marked variety. Mr. Worthington has recently written me: “I have received a lot of Nephele from New Hampshire and am surprised at the difference between them and the Illinois Nephele.”

The males of this last are almost black, the ocelli are very small and without rings. But in some examples there is a faint russet or yellowish tint about the ocelli, and perhaps on the space between them. On the under side the rings are russet or ochraceous, on both wings. The females are almost invariably and uniformly dark, and only occasionally is there a paler shade over the extra discal area of fore wings. Out of a number of females I find but one in which there is a clouded yellow space about the ocelli, and only three on which there are yellow, though hazy, ocellar rings. Of 16 ♂, 14 have 6 small ocelli beneath, 1 has 5, 1 has 2. Of 19 ♀, 2 have 6, 2 have 5, 6 have 4, 2 have 3, 6 have 2, 1 has 1. This form prevails exclusively to the Rocky Mountains. I have received it from Nebraska, Montana, Colorado and New Mexico, but Alope is unknown to me from that region.

In Can. Ent., ix., 141, 1877, I gave the history of Nephele, bred from eggs laid by a typical female from the Catskill Mountains, Hunter, N. Y. In fall of 1878, I wrote to several correspondents for eggs, and by their good will obtained many. Prof. Lintner and Dr. Bailey sent eggs of Alope from Albany, N. Y. Rev. Mr. Hulst, with the zeal and kindness which distinguishes him, crossed the rivers from Brooklyn to Hoboken, and brought away females of Alope, from which he obtained eggs for me. I got Alope eggs here at Coalburgh from three females. A friend at Hunter sent eggs of Nephele, and Mr. Worthington sent many of the Illinois form from Chicago. In each case the parent was sent with the eggs that the type might be noted. From Albany, Hoboken is 150 miles south; Coalburgh 800 miles southwest; Hunter is 35 miles southwest of Albany and of about 2,000 feet greater elevation. Chicago is about 800 miles northwest of Coalburgh and 1,000 west of Albany. So that the five localities are separated by considerable distances, and there has probably been no intercommunication at any time so far as these insects are concerned.

The eggs of the six lots were kept apart and as the larvæ hatched (at from 14 to 28 days from deposition, depending on the temperature), they were placed on sods in separate pots and left in the coolest room in my house. But some of the Illinois eggs were sent to Mr. C. P. Whitney, at Milford, N. H., who offered to put them on ice. I wished to try the effect of cold in retarding the hatching. Early in February I received the boxes again and found a number of healthy larvæ, with a few unbroken eggs. These last proved to be dead. The eggs had been sent in a paper pill box which was within a flat tin box, and this was set directly on the ice. The young larvæ when I received them were fixed to the rough sides of their box and had not been attacked by mould, the enemy most to be dreaded. Mr. Whitney wrote that he was notified in December that the ice-house was empty, and he thereupon removed the tin box without opening it, and placed it in a snow bank, where it remained till I sent for it. The larvæ may have been emerging from the eggs when he first received them, or perhaps did so in the interval between ice-house and snow. This method of keeping larvæ which become lethargic immediately upon leaving the egg will probably be found successful with all species of butterflies which have that habit—as the large Argynnids—and make it possible to breed them in numbers. I have been unable to find any other mode of wintering such larvæ without a certain loss of most of them.

On 23rd Jan., 1879, I transferred such of the Satyrid larvæ as were living (and this included some of each lot) to fresh sods, and 28th Jan. noticed that several were feeding. One Hunter Nephele passed 1st moult 23rd Feb’y, and before 4th March several of the same lot had passed the moult. But the Illinois Nephele and all Alope lingered. One Coalburgh Alope and one from Hoboken passed 1st moult 7th March, by which date the Hunter Nephele spoken of was swollen for 2nd moult, which it passed two days later. Two Illinois Nephele passed 1st moult 8th March. To the end some of the Hunter Nephele were in advance of all, and some of the Illinois examples lingered behind all. The stages of Coalburgh Alope were as follows:

1st moult passed7th March.
2nd ” ”21st ”1st to 2nd—14 days.
3rd ” ”14th April.2nd to 3rd—24 ”
4th ” ”2nd May.3rd to 4th—18 ”
In chrysalis26th ”4th to chrys.—24 ”
Imago issued9th June.chr. to imago—14 ”

Of Hunter Nephele I find no notes, but in 1877 the stages were

1st moultto 2nd—23 days.
2nd ”to 3rd—14 ”
3rd ”to 4th—14 ”
4th ”to chrys.—28 ”
Chrys.to imago—14 ”

Of Illinois Nephele the stages were:

1st moult passed8th March.
2nd ” ”21st ”1st to 2nd—13 days.
3rd ” ”9th April.2nd to 3rd—19 ”
4th ” ”26th ”3rd to 4th—17 ”
In chrysalis17th May.4th to chry.—21 ”
Imago issued30th ”chry. to im.—13 ”

The eggs of all these forms are alike, not to be distinguished from each other. They are conoidal, truncated at top and slightly arched; marked by about 18 vertical ridges running from base to top, the spaces between excavated roundly, and crossed by fine striæ; the top is covered with shallow cells, the outer ones irregularly hexagonal, the inner long and narrow about a central oval cell.

Nor can the larvæ of these forms be distinguished from each other up to second moult. The young, of first stage, are very peculiar and quite unlike what they become after first moult, as well as unlike all other Satyrid larvæ which I have bred. Under the microscope they look like the vertebræ of a fish, by reason of the many rows of long hooked bristles, those of upper and lower rows being curved back, the middle row forward. General color carnation, with a medio-dorsal line, and three lines on each side, all of crimson. After 1st moult the color is green, and the stripes, which are the same in number and position as the lines of first stage, are dark green; the hairs short and straight.

After 2nd moult the color becomes yellow-green and the stripes are changed. There is now a dark green one on middle of dorsum and a yellow one covering the ridge over the feet. On 24th March, I compared Hoboken Alope, Hunter and Illinois Nephele, of same age, all lately past second moult, and could see no difference whatever between them. Some Alope and Hunter Nephele were much covered with long hairs which were bent to the surface and gave them quite a shaggy appearance. But others did not show this peculiarity.

On 18th April, I compared Coalburgh Alope and Nephele from both localities, all past 3rd moult; length from .68 to .75 inch. All were yellow-green and in general alike; all had the yellow basal ridge, but in addition to this, the Illinois Nephele had a distinct longitudinal yellow stripe on upper part of side, and on either edge of the green dorsal stripe was a fine yellow line. The Hunter Nephele showed very faint traces of the yellow side stripe; the Alope none at all.

Comparing another Coalburgh Alope and Hunter Nephele a few days later, both past 3rd moult, neither showed traces of these lines and I could see no difference between the two.

At 4th moult all the Illinois Nephele, now .7 inch long, showed same peculiarities as at last stage. No other larva of the several lots presented the yellow lines so plainly at the same age, that is, just after the moult; but there were one or more Alope and Hunter Nephele which gave indications of the side line, and this came out more distinctly as the stage progressed. But most were without the side line.

Comparing mature larvæ:

One Albany Alope, length 1.25 inch, greatest breadth .16 inch; color very yellow-green, no yellow side or dorsal stripes or lines.

One Coalburgh Alope, length 1.6, gr. br. .2 inch; color yellow-green, the side more green than dorsum; a yellow side line, quite indistinct.

Hunter Nephele, 3 examples; length of one 1.2 inch, gr. br. .15 inch; of another 1.15, br. .16 inch. Two were yellow-green, of same shade as nearly all the Coalburgh larvæ. One was more decidedly yellow, with less green; but in none was there a yellow side stripe or the fine dorsal lines.

Illinois Nephele, length 1.36, gr. br. .14 inch. Color bright yellow-green, the dorsum more yellow than side; on the side as broad a yellow stripe as the one along basal ridge, and the green dorsal stripe edged by yellow.

Summary as to larvæ:

The five lots could not be separated before 2nd moult. After that, through the stages to maturity, the Alope from different localities and the Hunter Nephele varied somewhat in the shade of green, being more or less yellow; in some yellow prevailing on dorsum, green on sides; all had the yellow band on basal ridge, either pale or deep colored. If the yellow side line was present, as in some examples it was, it was indistinct, or obsolescent. They varied also in the hairy surface, some having the hairs short and upright, others long and bent down. The Hunter Nephele could not be distinguished from Alope by any permanent character.

The Illinois larvæ were deep yellow-green after second moult, and the side stripe was always present and distinct. The hairs were never long and bent. The larvæ were distinguishable from all the others.

Comparing chrysalids:

One Albany Alope, A; length .56 inch, greatest breadth .21 inch; color deep green, covered with smooth specks and patches of a lighter color, but which scarcely affect the general green hue; top of head case, ridge of mesonotum and ventral edges of wing cases cream color. This was the only one I obtained, and it produced a male butterfly.

One Hoboken Alope, same size and color, and produced a male.

One Hunter Nephele, length .6, br. .2 inch; was precisely like the Albany Alope in appearance, and produced a male.

Another Hoboken Alope; color yellow-green, and on the dorsum were three longitudinal yellow bands, one on middle of abdomen, ending at base of mesonotum, the others sub-dorsal, extending from last segment to head. This died before imago.

One Coalburgh Alope; length .8, br. .24 inch; bright yellow-green, covered with the lighter specks and patches, but not so as to obscure the ground; the wing cases clouded with darker green in long stripes; the three yellow dorsal bands as in the Alope last mentioned; edges of head, wing cases and mesonotum cream color. This produced a female butterfly, with broad yellow band and like the parent.

Another Coalburgh Alope, length .6, br. .22 inch; like the foregoing, being both banded and clouded. Produced a female butterfly, with broad yellow band.

One Hunter Nephele, B; color yellow-green, bands and clouding of wings present but indistinct. Produced a female.

Three Hunter Nephele; all yellow-green, with no bands or clouding; the edgings cream color. These all gave males. The chrysalis described Can. Ent., ix., 143, produced a female, but showed no band or clouds; the edgings cream color.

Two Illinois examples; length .6, br. .22 inch; color a pale blue-green, the powdery covering giving a whitish hue to the whole; no bands or clouds; the edges of mesonotum, head and wing cases white. Both these gave males. I obtained no females from this lot.

Summary as to chrysalids:

The largest Alope and Hunter Nephele were alike in color and in dorsal stripes, clouds on wings, and edgings of head case, etc.; but the bands and clouds were most distinct in Alope. All these large chrysalids produced female butterflies. The plainer and smaller chrysalids were male. But one female Nephele chrysalis is recorded as without clouds or bands.

The Illinois chrysalids were of same shape as the rest, but were small and plain colored, and were blue or whitish-green; the edgings white instead of cream color. They were readily to be distinguished from any other.

Results in butterflies:

The chrysalis A, Albany Alope, gave a male not differing from many males taken at Hunter, and which there I always regarded as true Nephele, though off type, being without band, but with a narrow yellow nimbus about the ocelli and connecting them, the edges everywhere fading into the black ground.

On the other hand, the chrysalis B, Hunter Nephele, gave a typical female Alope, with a broad and clear yellow band. The female which emerged in 1877 from the Hunter Nephele before spoken of had both ocelli surrounded and connected by yellow, and stood midway between the types of the two forms.

The two chrysalids from Illinois, as I have said, gave males; one wholly dark, the irides without rings; the other had a faint russet nimbus about them, and over the intervening space was a tint of russet.

The Coalburgh chrysalids produced typical Alope, with broad yellow bands, and like the females which laid the eggs. Therefore outside the belt of dimorphism Alope produced Alope, but inside the belt Alope produced Nephele and Nephele produced Alope.

In conclusion:

In Canada the typical Nephele is the only form representing the genus Satyrus, except that possibly in some localities Alope or intergrades may appear; but if so, it is only occasionally. In New York and part of New England a belt of latitude is passed where in one section or other both these forms fly, besides an endless variety of intergrades. Finally, Alope emerges in the south from this belt as the only form, and inhabits a broad zone, which ends about with the southern line of North Carolina and of Tennessee, but at the southwest flies in parts of Texas, and has become slightly modified when compared with the Alope of the middle States. And to the west, somewhere between New York and Illinois, Alope disappears, and a slightly changed form of Nephele presents itself, and occupies the country to and on the eastern slopes of the Rocky Mountains. In some cases this cannot be distinguished from the typical Nephele, but as a whole, it has taken a departure, and has come to have differences in its larva and chrysalis. I call this form variety Olympus (after the companion of the satyr Marsyas when the latter had his little difficulty with Apollo).

The relationship between Alope and Nephele is in good degree paralleled by L. Arthemis and Proserpina, the first of which occupies the northern half of the Continent, but is dimorphic with the other in a belt of latitude which passes through the northern States from Maine to Wisconsin. Proserpina emerges from this belt on the south, and grades imperceptibly into Ursula, which last changes gradually till it has acquired a type, in Arizona, as different from that in which it manifests itself in Pennsylvania as the Texan Alope is from Alope of New York. This belt is nearly coterminous on both north and south with the belt of dimorphism in the Satyrids. It is worthy of note also that the dimorphism of P. Turnus begins inside this belt.

In this last-named species it has been supposed that the melanic form (confined to the female, Glaucus) first originated by accident, and was afterwards perpetuated and obtained an advantage over the yellow form, and finally in good degree supplanted it throughout its southern area, and that the existence of enemies had much to do with the suppression of one form, while their absence favored the other. What influence has gradually transmuted Alope into Nephele it is difficult to conjecture. It could not here be the presence or absence of enemies which has affected one or other form. And if it is climatic, what can there be in common between the climate of Canada and Illinois which encourages Nephele and extinguishes Alope?

In a second paper I shall speak of Pegala and the Pacific species of this genus.

[1] I shall be greatly obliged to any readers of this who will give me information as to the occurrence of Nephele or Alope west of New York. Two plates of Part IX Butterflies of North America will be devoted to the illustration of these forms and varieties, and intergrades, and I desire to make the history of the species as complete as possible in the text.