Wm. S. Creighton.
A New Subspecies of Crematogaster minutissima with Revisionary Notes Concerning that Species. (Hymenoptera: Formicidæ).
Psyche 46:137-140, 1939.

Full text (searchable PDF, 280K)
Durable link: http://psyche.entclub.org/46/46-137.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.

19391 A New Subspecies of Crernatogaster 137 A NEW SUBSPECIES OF CREMATOGASTER
MINUTISSIMA WITH REVISIONARY NOTES
CONCERNING THAT SPECIES.
(HYMENOPTERA :FORMICID^E)
BY WILLIAM S. CREIGHTON
College of the City of New York.
In 1895 Carlo Emery published the second half of his mon- ograph dealing with North American ants. A considerable proportion of the material on which this work was based had come to Emery from Pergande who was, at that time, con- nected with the National Museum. As a general rule Per- gande gave no names to the ants which he sent to his col- league probably because, in most cases, he was not sure as to what was new. In the instance which I wish to discuss here, however, Pergande had not only recognized the form as new but had selected the name which it now bears. There seems to be no other interpretation which can be placed upon Emery's treatment of Crematogaster victima subsp. missouriemis. Emery attributed this form to Pergande, stating that the latter had used the name in litteris. There is no method whereby one can determine whether Pergande was actually preparing to publish a description of missouriensis and it makes very little difference if he was. Emery accompanied his citation of the form with a brief characterization per- mitting its recognition. This, of course, is the original de- scription of rnissouriensis, which is to be attributed to Emery and not Pergande. I do not doubt that many would regard this as a flagrant case of name-grabbing but it is by no means certain that such was the case. It is difficult to believe that Emery supposed that he could give missouriensis to Per- gande by merely citing him as author. It seems more prob- able that Emery was under the impression that Pergande would publish the description of the new form before the appearance of his (Emery's) monograph and that he inad-



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

138 Psyche [December
vertently let slip into print a manuscript notation which was to have been subsequently altered. It is easier to be tolerant of this mistake than it is to agree with Emery's treatment of the taxonomic status of missouriensis. I can see no reason why he should have assigned it to victirna instead of to Mayr's minutissima. In 1870 Mayr had published a key to the New World species of Crematogaster in which he clearly distinguished between the characteristics of Smith's victima and his own minutissima. Emery must surely have employed Mayr's key and just as surely he should have been aware that rnissouriensis is more closely related to minutissima than to victima. The distinct areas of cephalic punctures which are present in vietima, are absent in the other two forms. In recent years the recognition of a number of addi- tional subspecies has considerably expanded the specific limits of victima. Even so the above contention can be de- fended. Still more peculiar is Emery's disregard for zoogeo- graphical considerations. When he assigned misso@ensis to victima the latter species was known only from Brazil. It would certainly have seemed more logical to consider the possibility of relationship with a species which had been found in the Gulf Coast region. As far as I can determine no one has ever questioned Emery's judgment in the matter. Despite this I believe that missouriensis should be regarded as a northern race of minutissima. In addition there is a western race which is described below.
Crematogaster (Orthocrema) minutissima thoracica subsp. nov.
The subspecies thoracica differs from the typical form and the subspecies rnissouriensis in its distinctly more shining thoracic dorsum. In both the other two forms the dorsum of the promesonotum bears, in addition to longitudinal rugse, a number of fine and fairly close-set punctures. These punctures, while not dense enough to produce an opaque appearance, dull the surface to a considerable extent. They are not present in the subspecies thoracica. In addition thoracica usually lacks longitudinal rug= on the pronotum and, when they are present, they appear to form a wavy border at the extreme edge of the pronotum. The longi-



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

19391 A New Su,bspecies of Crematogaster 139 tudinal rug= in the typical minutissima are well developed and at least two of them lie well in towards the center of the pronotum. In missouriensis the rugse are variable in posi- tion but when they occur at the edge of the thorax, as fre- quently happens, they are more prominent than in thoracica. The shape of the petiole seen from above is usually quite characteristic in thoracica. The sides gently diverge behind so that the petiole is widest at the rear. The difference is not great but the wedge-like appearance is rather different from that of the other two subspecies, where the petiole is more quadrate with the sides subparallel and widest, if there is much difference in width, at the middle. The epinotal spines of thoracica are short like those of the typical form. In other respects thoracica is very similar to the typical minutissima. Described from a series of workers taken by W. M. Mann in Miller Canyon, Huachuca Mountains, Arizona (elevation 6000 ft.). In addition to this type series I have seen other specimens also secured by Dr. Mann, in Ramsey Canyon (elevation 5800 ft.) in the Huachucas.
Holotype (worker) and a series of paratypes in the col- lection of the Museum of Comparative Zoology. Additional paratypes in the collection of the American Museum of Natural History and the collection of the writer. The three subspecies of minutissima and our single re- maining species in the subgenus Orthocrema, Cr. (0.) ari- zonensis, may be separated as follows :
1. Tip of the antennal scape in repose notably surpassing the occipital border; color yellow ; the gaster clothed with abundant long hairs ._-..._..-._---.--.._---.-..-._ÌÔ.-.ÌÔ.- 2 Tip of the antennal scape in repose failing to reach the occipital border ; color piceous brown ; the erect hairs of the gaster short and sparse : __.-__----,.,.-...-. arizonensis 2. Dorsum of the promesonotum very smooth and shin- ing; rugas, if present, feeble and confined to the edge of the pronotum : .--.-----...-.-......... minutissima thoracica Dorsum of the promesonotum finely punctate in addi- tion to the longitudinal rugse, the surface feebly shin- ing; rug= well-developed and often placed towards the center of the thorax _-Ì£_--._.---_-.-..-._._-_--ÌÔ._-.ÌÔ.ÌÔ 3



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

140 Psyche [December
Epinotal spines about one-half as long as the distance which separates their bases and rather strongly di- rected upward; pronotum with the rug2 usually lat- eral in position : minutissiwm missourimsis Epinotal spines less than half as long as the distance which separates their bases and directed more back- ward than upward; pronotum with two prominent rug= near the middle :---..,-...minutissima minutissima



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