STUDIES OF NEARCTJC (RHOPALOCERA, SATYRIJDAE) COENON0YMPHA TULLIA INORNATA 0 ~~EDWARDS F. MARTIN BROWN :ULEI .~~~~O THE -AMERICAN MUSEUM OF NATURAL HISTORY~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ rVLM .0: ARIL NvVYR:15 4 STUDIES OF NEARCTIC COENONYMPHA TULLIA (RHOPALOCERA, SATYRIDAE) STUDIES OF NEARCTIC COENONYMPHA TULLIA (RHOPALOCERA, SATYRIDAE) COENONYMPHA TULLIA INORNATA EDWARDS F. MARTIN BROWN Fountain Valley School Colorado Springs, Colorado BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY VOLUME 105 : ARTICLE 4 NEW YORK : 1955 BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY Volume 105, article 4, pages 359-410, text figures 1-19, plates 28, 29, tables 1-21 Issued March 14, 1955 Price: $.75 a copy INTRODUCTION THE INSECTS that compose the superspecies western parts of the Great Basin and the tullia are quite variable. Apparently they are southern part of Oregon is a small cluster of sensitive to environmental conditions and as forms that have these characters in common: a whole represent plastic and probably they are ocellated, very pale in color, and are "young" species. The shuttling about that clearly two brooded. This is california West- has been forced upon these insects in North wood and Hewitson. Two other names are America by the vacillation of the Pleistocene applied to these insects: galactinus and ice sheets has caused considerable differentia- eryngii. The former seems to be merely a tion among populations. When series from brood name; the latter may represent some well-separated localities are studied they ap- degree of hybridization with the adjacent pear to represent sharply defined species and form, ampelos. subspecies. That this is an illusion can be On the west coast, north of California, and demonstrated by study of material from in the basin-range region, there flies a group many localities across the continent. With the of forms that are without ocelli and lack the possible exceptions of mixturata Alpheraky in light basal patches on the under side of the the subarctic and subfusca Barnes and hind wings. They are very much like inornata Benjamin from Arizona there are no well-de- in this respect. However, at least the southern fined and clearly segregated forms of tullia in members of the group are double brooded, North America, yet there are definite trends and all are much lighter in color. For the in variation that are widespread and deserve time being I prefer to hold them apart from recognition. the eastern moiety. The oldest name avail- The problem that faces the taxonomist is able in the group is ampelos Edwards. From when to stop in naming populations. I shall south to north we find these named entities: face this by avoiding it. There is an abun- elko, ampelos, insulana, sweadneri, and col- dance of names available. To recognize any umbiana. further segregates would necessitate recog- Lastly, in Alaska there flies the Asiatic nizing literally dozens of them. insect mixturata Alpheraky. It lacks ocelli There seem to me to be four or five distinct and the light basal patches and most cer- groups of related forms comprising the super- tainly is single brooded. On the under side species in the Nearctic. The easternmost of of the hind wings there are areas of strongly these is best called inornata Edwards. Essen- contrasting colors. Yukonensis may be iden- tially this is a group of insects that are almost tical with mixturata; kodiak is closely related free of ocelli, lack light basal patches on the to it. under side of the hind wings, and with rare Schwanwitsch's postulated ancestral Co- exceptions are single brooded. Five names enonympha is much like C. haydeni Edwards. have been suggested for variants in this This suggests that the presense of ocelli is group. From east to west these are mcisaaci, more primitive than their absence. The geo- nipisiquit, quebecensis, inornata, and ben- graphic position of the most ocellated mem- jamini. bers of the superspecies in America, the In the Rocky Mountains and the Great southern periphery of the species range, tends Basin lives a group of tullia forms that may to support Schwanwitsch's contention. Thus be characterized as ocellated, with two basal the ochracea moiety may lay claim to being light patches on the under side of the hind the modern carriers of the more primitive wings and, although usually single brooded, characteristics of pattern. This claim must with a second or partial second brood occur- be shared with california. At this point it ring more frequently than among inornata. may be of interest to note that members of The oldest name that is available for this both these moieties are in all probability group is ochracea Edwards. In it we find from those least disturbed by the repeated move- south to north the insects called fusca, furcae, ments of the continental ice sheets and alpine brenda, mono, ochracea, and mackenziei. glaciers of the Pleistocene. There is no reason In California and invading the extreme to believe that they had to make long treks to 363 364 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY VOL. 105 maintain themselves in hospitable environ- to believe that tullia invaded North America ments. It is possible that their present-day after the last great retreat of the ice, I must pattern of life parallels closely that of the consider that they are insects that were suc- ancestral invader that established the super- cessful in following their habitat as it moved species tullia in America. south and north with the flow and ebb of the If these ocellated insects are accepted as ice sheet or sheets. the modern representatives of ancestral tullia Paleobotany has revealed that the lower most nearly like that ancient one, then in- Mississippi Valley, as far south as Louisiana ornata generally lacking ocelli and the light and central east Texas, and the Atlantic basal patches may be considered a more coastal plain of the southern states, harbored modern development from the ancestral a forest that at the peak of the Wisconsin stock. Such a condition may have developed glaciation contained characteristic elements on this continent or it may have developed in now associated with the Boreal Forest of Asia, and inornata may represent a more re- Canada. It seems likely that this forest ex- cent invasion than that of ochracea and cali- tended southward from no great distance in fornia. A thoughtful consideration of all the front of the ice, possibly not more than a factors leads me to believe that such an in- hundred miles, to the Gulf coast and northern vasion must have been at least pre-Wiscon- Florida. Thus the minimum distance traveled sin, if not earlier. I can accept an invasion of by the inornata moiety lies between 1200 mixturata during or since the Wisconsin ice and 1800 miles. Such southing and northing sheet but of no other Nearctic tullia. imposed upon the wanderers environmental If we accept a pre-Wisconsin date for the strains that must have been rigorous in sort- advent of inornata in North America, the ing out the individuals fitted to survive. No present insect has survived many vicissitudes. such pressures were brought to bear upon Today it occupies land that has been covered any of the western moieties. As a result the from once to three or four times by the con- inornata moiety is capable of enduring much tinental glaciers. In fact there are relatively more environmental variation in its present few places where inornata is now found that range than are the others. The various expres- were not glaciated. In the light of recent evi- sions of inornata are at home from the cool dence from carbon-14 datings, the southern- humid maritime areas about the mouth of most areas now occupied by inornata have the St. Lawrence River to the warm dry been free of ice for about 11,000 years and the prairies, whereas the neighboring ochracea northernmost areas for something less than moiety (except mackenziei, the history of half of that time. Because I do not agree with which will be traced in another article) is some students of the genus who are inclined restricted to the semi-arid warm areas. COENONYMPHA TULLIA INORNATA EDWARDS EAST OF THE Rocky Mountains from the ical variation in its range. Thus everything border states northward to the upper reaches from the Rockies to Newfoundland would be of the Mackenzie River and eastward to the called Coenonympha tullia inornata Edwards. Atlantic coast from northern New Brunswick If it were not for the Holarctic character of to Newfoundland and Great Whale River on tullia, inornata could be accepted as a weakly Hudson Bay is found a group of related forms defined species. If the moiety be accepted as of tullia that are best considered a single a species (and it has been by such nomen- variable subspecies or weakly developed clatorial specialists as McDunnough and dos species, depending upon one's particular Passos), then the various environmental ex- point of view. The Coenonympha found in pressions assume the position of subspecies. this area by no means form a homogeneous Either of these solutions fits the Rules. How- population. They represent a series of inter- ever, the simplest solution is not always the grading populations. As more and more series best one. The taxonomist is faced with the are collected from different localities spread task of naming the recognizable plants and across the range of the insect it becomes in- animals in such a way that the biologist can creasingly difficult to separate what formerly accurately designate the subject of his appeared to be several valid subspecies. studies. At times the solution to this problem The oldest acceptable name for this group seems impossible.