Wm. S. Creighton.
Studies on Arizona Ants (4). Camponotus (Colobopsis) papago, a New Species from Southern Arizona.
Psyche 59:148-?, 1952.

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STUDIES ON ARIZONA ANTS (4)
CAMPONOTUS (COLOBOPSIS) PAPAGO, A NEW
SPEICIES FROM SOUTHERN ARIZONA1
BY WM. S. CREIGHTON
Department of Biology, College of the City of New York This paper deals with ten colonies of Colobopsis taken by the writer in southern Arizona during the summers of 1950 and 1951.
The work done during the second sum-
mer was made possible' by a fellowship from the John Simon Guggenheim Memorial Foundation. Most of the observa- tions on habits carried in this paper were made during the first months of a fifteen month survey of the ants of the southwestern United States and northern Mexico. I am happy to take this opportunity to express my sincere appreciation for this fellowship. I wish to thank Mr. Harry Stevens, the United States Agent in charge of the Papago Indian Reservation at Sells, Arizona, for his kindness in permitting us to use the Forestry Cabin on the western slope of the Baboquivari Mountains. We are also grateful to Mr. and Mrs. Forrest Perkins, who generously turned over their ranch house to us during our stay on the eastern slope of the Baboquivaris. The comfortable surroundings provided in each case greatly facilitated the work with the ants.
The older records for the species described in this paper were regarded by W. M. Wheeler as representatives of C. (Colobopsis) cerbemlus Emery. For reasons which will be given later, I feel that it is a much sounder procedure to treat this ant as a new species. To do so involves the risk that it may subsequently prove to be cerberulus, as Wheeler supposed. But this risk must be taken if we are ever to get out of the fog which has obscured cerbendus from the time of its original recognition. In 1920 Emery described cerbendus from a single, winged female taken in the state *Published with a grant from the Museum of Comparative Zooloey at Harvard College.




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19521 Creighton - Cawonotus papago 149
of Michoacan, Mexico (1). It is hard to understand why Emery felt that this specimen should be named. During the fifty years of entomological work which lay behind him, Emery had often struggled with the difficulties that result whenever a new species of ant is based on a dis- sociated female. Moreover, by 1920 the importance of ac- curate field data to an original description was clearly recognized. Yet Emery elected to describe an insect which wholly lacked significant field data. That the ant was known to have been taken in Michoacan is of scant signi- ficance, for that state has a singularly diverse topography and a corresponding diversity of biotic associations. Final- ly, Emery's description of cerberdus was brief and without figures. It was certain from the start that this description would be a source of trouble for, under the circumstarices, nothing but a miracle could prevent subsequent confusion in the case of cerbemlus.
Most of Emery's short description of cerberulus con- sists of a comparison of his unique type with the female of Wheeler's etiohtus. From the nature of this compari- son it is evident that Emery had specimens of etiolatus at the time that he wrote the description of cerberulm. When Wheeler described etiolatus in 1904 (2) he presented no figure of the female and his description of that caste lacks certain features which Emery later cited. It is certain, therefore, that Emery had authentic material of etiolatus, probably from that part of the type series which Wheeler sent to Forel. It would otherwise have been impossible for Emery to have presented the characterization of the etiolatus female which he used in his comparison with the female of cerberdus.
The fact that this comparison utilized the female of etiolatus may well be what led Wheeler to believe that he could recognize the essential features which distinguish cerbemlus; for Wheeler had type females of etiolatus in his own collection and with these as a guide he could secure a much more exact idea of the female of cerberidus than would be expected from Emery's brief account of that insect. It is now certain that Wheeler overestimated the utility of Emery's description. It is good enough to



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160 Psyche [December
give a general idea of the female of cerbervlus but it lacks the finer points which are necessary for the work that Wheeler attempted.
In 1920 Wheeler had in his collection a number of males and females of Colobopsis taken in southern Arizona. These specimens came from Texas Pass in "the Dragoon Mountains, Sabino Basin in the Santa Catalina Moun- tains and Black Dike Prospect in the Sierrita Mountains. The specimens from Texas Pass had been taken by Wheeler at light. No field data accompanied the other specinnem: Soon after .Emery published his description of cerbervlus, Wheeler identified the above specimens as that species. But no reference was made to them until 1934. In that year Wheeler published a paper (3) in which he attributed the Arizona material to eer'bamius. He also described as cerbendus three major workers which Dr. Elizabeth Skwar- ra had collected near the city of Vera Cruz, Mexico. These specimens were taken in a hollow spine of Acacia sphaero- ceyhala, Wheeler's association of the Arizona, females with the Michoaean type was made on the basis of Emery's des- cription. This could be defended, since the same caste waa involved in each case. but the association of the Vera Cruz majors with cerbendus was a different matter. It was baged on a comparison of the Vera Crux majors with the Arizona females and on Wheeler's unsupported belief that the former represented the unknown major caste of cerbervlw. I was forced to deal with this extraordinary double asso- ciation when I was preparing the Colobopsis section of The Ants of North America (4). Since I could see no possibility of validating Wheeler's treatment of the Vera Cruz majors.. cerbemlus was omitted from the key. I commented on certain geographical discrepancies, which made Wheeler's association seem unlikely, but pointed out that there was little hope for bettering the matter until someone secured a nest of this ant in which both major worker and female were present.
It was, therefore, very gratifying to find such a colony in Garden Canyon, Huachuca Mountains, in July 3.950. This colony was a fragment of a larger one, to judge from those subsequently taken, for it contained only eight in-



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19521 Creighton - Camponotus papago 151
dividuals. One of these was a dealated female, three were major workers and four were minor workers. The nest
was found in a dead limb of Quercus emoryi. As soon as possible I took this nest to Harvard for comparison with material identified as cerberulus in the Wheeler Collection. This was put at my disposal through the courtesy of Dr. Joseph Bequaert whom I wish to thank for this kindness. The material labelled as cerberulus in the Wheeler Collec- tion oonsisted of Skwarra's specimens from Vera Cruz and a series of females from Texas Pass in the Dragoon Mountains. To save possible confusion in the future it seems well to note that on the locality lab8els of these speci- mens the name is mispelled as the "Dragon Mountains". Texas Pass is a low pass at the western end of the Dragoon Mountains, through which the highway between Willcox and Benson now runs. The specimens from Sabino Basin and Black Dike Prospect, which Wheeler mentioned in 1934 could not be found. It is probable that these speci- mens are now in the collection of the American Museum of Natural History.
As I 'had expected, the female from Garden Canyon proved to be identical with those from Texas Pass. But the Garden Canyon majors were not the same as those from Vera Cruz. I have presented the differences in detail on a subsequent page. They need not be discussed here other than to state that, in my opinion, these differences clearly show that the two insects belong to separate species. While the above comparison does not cover the second part of Wheeler's double association, it has given results significant to it. The head of the major of Colobopsis, like that of most species of ants in which this caste is present, differs more or less from that of its accompanying female. But there is no rule which governs the degree of difference. The amount of differentiation varies with the species and this circumstance defeats any attempt at anticipating the finer structure of one caste from that of the other. Since this is the case it should be obvious that nothing can be done with cerberulus until the unique female type can be proven identical with a female whose major worker is known. That this could be done by using Emery's



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152 Psyche [December
description appears to the writer to 'be utterly impossible. Nor do I believe that a comparison of Emery's type with material now present in American collections would neces- sarily be conclusive. Since the Vera Cruz specimens are specifically different from those which occur in southern Arizona, there is good reason to suppose that the Michoa- can type is als'o different. In all likelihood, therefore, a comparison of Emery's type with females taken in southern Arizona would merely substitute a new problem for an old one. For, unless the two proved identical, we would still have no idea as to the characteristics of the major of cerberulus. In all probability the nature of Emery's cer- bendus will remain enigmatical until extensive collections of arboreal ants can be made in Vera Cruz and Milchoacan. When complete colonies of Colobopsis can be taken in these states and compared with Emery's type the primary dif- ficulty in the cerberzdus problem may be overcome. But we cannot wait until this is done to deal with a secondary difficulty which has resulted from Wheeler's un- fortunate association. Since the Vera Cruz majors are specifically different from specimens coming from southern Arizona, the least that can be done is to provide a new name for one or the other of these insects, in order that the two species can be handled without violating nomenclatori- a1 rules. I am convinced that it is best to treat the Arizona material as a new species for the following reasons: ( 1 ) . If only one new name is proposed the remaining species will have to be considered as cerberulus until this can be definitely authenticated or certainly disproved. (2). From the standpoint of proximity it is much more likely that the Vera Cruz majors should be the same as the type of cerberulus. Southern Arizona lies seven hundred miles to the north of Vera Cruz and Michoacan. But the two states themselves are separated by less than two hun- dred miles and they lie in approximately the same latitudes. (3). Any additional description in the case of the cer- berulus complex should deal with adequate material about which there must be no occasion for speculative associa- tion. The Arizona material fully meets this condition. The Vera Cruz majors obviously do not. In connection



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19521 Creighton - Camponotm papugo 153
with this last point it seems worth noting that in the ten colonies on which this study was based there were 23 fe- males, 2 males, 104 major workers and 194 minor workers. These totals do not include 20 additional females taken at light.
There follows the description of the above material: Camponotus ( Colobopsis) papago sp. nov. Major worker: head 1.06 mm., thorax and petiole 1.5 mm., overall1 len4gth 4.5 mm. (Plate 13, figure 3) Truncated portion of the head distinctly concave, with a low, serrate flange bordering either cheek but not con- tinued across the top of the clypeus. The entire clypeus raised slightly above the level of the adjacent portions of the cheeks, which slope downward to the clypeus from the bordering flange. 'Sculpture of the truncated portion of the head consisting of coarse, irregular ridges which form reticulations. These reticulations and the areas which they surround, are covered with numerous, very fine, crater-like punctures. These punctures do not dull the shining surface. Sculpture on the mandibles rough but not distinctly reticulate. Seen from above the frontal lobes are covered with even reticulations which surround circular or nearly circular depressions. This reticulate sculpture extends almost to the level of the single median ocellus, with the depressions becoming shallower and more widely spaced towards the rear. The rear third of the head is finely shagreened and notably more shining, par- ticularly at the occipital corners, than is the heavily sculp- tured front of the head. The reticulation on that part of the clypeus which lies behind the truncation is much less even than that on the frontal lobes. Reticulation on the cheeks less even and somewhat coarser than that on the frontal lobes. The entire anterior half of the head with the same fine,
crater-like punctures which occur on the truncated portion. A very feeble frontal furrow is visible in certain lights. Antenna1 scapes rather strongly shin- ing with small, white, appressed hairs. Hairs on the trun- cated portion of the clypeus and on the front face of the mandibles very strongly clubbed and shaped like tear drops. Hairs along the outer border of the mandibles, on the



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154 Psyche [Dftcember
frontal lobes and on the sides of the head behind the trunca- tion Iong', curved, blunt and often clavate but rarely aa strongly clubbed as those of the clypeus. Thorax, petiole and gaster more finely shagreened than the head with the surface strongly shining. In addition to the shagreening there are very small scattered punctures present, from which arise short, delicate, fully appressed hairs. No erect hairs present on the thorax, those on the crest of the petiole very short and fine. Erect hairs rather sparse on the gaster, mainly confined to the row at the posterior edge of each segment. Legs finely shagreened and strongly shining with delicate, appressed hairs like those of the thorax. Fore femora expanded dorso-ventrally and strongly compressed laterally. The tarsal joints and the funiculi covered with abundant, short, yellowish, semi- erect hairs. Color deep blackish brown, the anterior third of the head clear yellowish brown. Tarsi, funiculi, base of the petiole and the autures of the thorax light brown. Worker minor: head 0.9 mm., thorax and petiole 1.25 mm., overall length 3.25 mm. (Plate 13, figure 2) Head, seen from the front, with the eyes notably more convex than those of the major, the sides in front of the eyes narrowing to the insertion of the mandibles. Mandi- bles with four well-developed teeth. Clypeus moderately convex from side to side, somewhat more strongly convex from front to rear, ecarinate or with a very blunt and in- distinct carina, Frontal lobes together forming a trap- ezoidal area which is a
little wider behind than in front.
Frontal groove absent. Occiput evenly convex, the lateral portions meeting the posterior border of the eyes without any distinct posterior angles. The antenna1 scape, when extended straight to the rear, surpasses the occipital border by an amount slightly less than its greatest thickness. Head, thorax and abdomen moderately shining with a rather strong, reticulate shagreening. Appressed hairs as in the major and female. Erect hairs long, tapered and with sharp tips. They are rather numerous on the man- EXPLAHATION of PLATE 13
Campmotw (COSobqmis) -0. Fig. 1. Female. Fig. 2. Minor worker. Fig. 3.
Major worker. (All figures drawn to same scale.)



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156 Psyche [December
dibles and clypeus, sparser on the front and represented on the occiput by a single pair. Thorax without erect hairs. Crest of the petiole with several very short, delicate erect hairs. Erect hairs on the gaster widely and rather evenly spaced over the dorsum except at the base of the first seg- ment, which is hairless. Fore femora laterally compressed as in the major. Color: blackish brown, the mandibles and tarsal joints light brown.
Female: head 1.25 mm., thorax and petiole 2.3 mm., overall length 6.0 mm. (Plate 13, figure 1) Head similar to that of the major but with all three ocelli large and prominent. Sculpture on the truncated Text-figure 1. Upper suiface of the head of the major worker of Campon~tus (Colobopsis) papggo sp. nov.
portion of the head identical with that of the major. Re- ticulate sculpture on the frontal lobes smaller and shal- lower than that of the major and not extending as far back on the head. Eyes distinctly larger and more convex than those of the major. Hairs on the mandibles and the truncated portion of the clypeus longer and less clubbed than those of the major.




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19521 Creighton - Camponotus papago 157
Thorax feebly shagreened and rather strongly shining, with small, scattered, appressed hairs as in the major. Erect hairs absent on the thorax except for a pair of long, yellowish hairs which arise from the scutellum. Gaster more feebly shagreened and more strongly shining than the thorax but with similar appressed hairs. Erect hairs
on the gaster only moderately abundant, mostly confined to a row at the rear of each segment. Erect hairs on the terminal gastric segment distinctly longer than those else- where. Fore femora laterally compressed as in the major. Color blackish brown, the anterior quarter of the head, much of the scutum and the middle and hind tarsi yellow- Text-figure 2.
Truncated surface of head of major worker of CamW- notus (Colobopsis) papgo sp. nov.
ish brown. Wings hyaline, iridescent and with pale yel- lowish veins.
Male: Head 0.7 mm., thorax 1.5 mm., overall length 3.5 mm.
The sides of the head in front of the eyes taper slightly from the anterior edge of the eye to the insertion of the mandible. Behind the eyes the sides of the head are evenly



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158 Psyche
[December
convex from the rear edge of the eye to the lateral ocellus. The occipital border is 'slightly concave between the lateral ocelli. Anterior border of the clypeus feebly sinuate. Man- dibles small, somewhat spatulate and with the teeth repre- sented only by a V-shaped notch on the masticatory margin. Antennal scapes long, surpassing the occipital margin by a little more than one-third their length. The greatest width of the thorax, when seen from above is approximately equal to that of the head. In profile the neck of the pronotum is short, the anterior face of the scutum is evenly rounded and its dorsal face is flat and on the samie level as the anterior edge of the scutellum. The latter is convex in profile and descends sharply in the rear. In profile the epinotum is depressed well below the level of the scutellum, rounded and without a good separation between the basal and declivious faces. Petiole with a short but distinct anterior peduncle, the node low in profile, taper- ing slightly from base to crest with the latter evenly rounded. Seen from above the node of the petiole is trans- versely oval, with the width about twice the thickness from front to back. Gaster approximately as long as the thorax. Genitalia small and obscure.
The surface is moderately to strongly shining. Front and genae strongly shining with scattered punctures. Oc- ciput and scutum less shining with a delicate reticulate sculpture. Scutellum very shining with scarcely any sculp- ture. The remainder of the thorax and the node of the petiole with a reticulate sculpture which is less pronounced than that of the scutum. Gastric sculpture very feeble, shagreened but scarcely reticulate, the surface more shin- ing than that of most of the thorax. Sparse erect hairs are present on the head, the coxae and the gaster. Thorax without erect hairs. Antennal scapes, the femora and the tibiae with very delicate, short, sparse hairs which are fully appressed. Pubescence on the antenna1 funiculi and the tarsal joints suberect and not particularly prominent. Tho- rax and gaster dirty, yellowish brown, the head distinctly darker. Wings hyaline and iridescent with the veins very pale.
Types of female, male, major and minor worker deposited



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19521 Creighton - Camponotzis papago 159 in the Museum of Comparative Zoology, Camlbridge, Mass. The type locality is Forestry Cabin (Baboquivari Canyon), Baboquivari Mts. (3500'), Arizona. The type nest was taken on July 24, 1951 in Quercus emoryi. Four other colo- nies were taken in this same station. In addition four more colonies were secured near Perkins Ranch in Brown Canyon on the eastern slope of the Baboquivari Mountains. These last colonies were situated at elevations between 4100 and 4600 feet. Mention has already been made of the single colony taken in Garden Canyon in the Huachuca Mountains. The elevation of the station from which this colony came was 5800 fee1t.l
In the following paragraphs are given the results of the comparison between the major workers of papago and the three major workers from Vera Cruz which may be cer- b erulus :
1. In papago the length of the head is shorter in pro- portion to its width and the sides of the head in front of the eyes are slightly convex when the head is viewed from above. In the Vera Cruz majors the sides of the head in front of the eyes are straight or nearly so when the head is viewed from above.
2. In papago the scape only slightly surpasses the oc- cipital margin. The amount of the scape which projects beyond the margin is notably less than the greatest dia- meter of the scape. In the Vera Cruz majors the scape surpasses the occipital margin by an amount equal to the greatest diameter of the scape.
3. In papago the triangular lateral portion of the man- dible is feebly and irregularly concave on its anterior face. In the Vera
Cruz majors the triangular, lateral portion of the mandible is so strongly concave on its anterior face that the tip of the triangle appears to point forward. 4. In papago the truncated portion of the clypeus is uniformly covered with coarse, reticulate ridges. In the Vera Cruz majors this portion of the clypeus is also reticu- Since the above was written nests of C. papugo have been taken by the writer in Cottonwood Canyon, Peloncillo Mfcs. (4800'1, Arizona and
fourteen miles north of Imuris, Sonora
(3200'1, Mexico. In both cases
the ants were nesting in Q. emoryi.




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