Paul B. Kannowski.
Notes on the ant Leptothorax provancheri Emery.
Psyche 64(1):1-5, 1957.

This article at Hindawi Publishing: https://doi.org/10.1155/1957/51839
CEC's scan of this article: http://psyche.entclub.org/pdf/64/64-001.pdf, 476K
This landing page: http://psyche.entclub.org/64/64-001.html

The following unprocessed text is extracted automatically 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
Vol. 64 March, 1957 No. 1
- --
NOTES ON THE ANT
LEPTOTHORAX PROVANCHERI EMERY
BY PAUL B. KANNOWSKI
Department of Biology
University of North Dakota
The ant, Leptothorax provancheri Emery (= L. emer- soni Wheeler, L. e. glacialis Wheeler, and L. e. hirtipilis Wheeler), is interesting because of its peculiar habits, rare occurrence, and unusual distribution. It has long been known as an inquiline in the nests of Myrmica bre- vinodis Emery, and, until recently, it was thought that this relationship was obligatory on the part of provancheri. Cole (1954, p. 241) indicates that this species is able to live independently (under stones), at least in the moun- tains of New Mexico. The habits of provancheri were first noted by Wheeler (1901). He had discovered that its nests were intimately connected with the galleries and chambers of Myrmica, brevinodis nests. In this and a later paper (1903a) on provancheri, Wheeler presented an in- teresting and detailed analysis of the symbiotic relation- ship between provancheri and its host.
Wheeler stated that the nests of these two ants were found in the Litchfield Hills near Colebrook, Connecticut, "under some small stones that were rather deeply im- bedded in the moss bordering the exposed glaciated rock of the hilltop" (1901, p. 432). The habitat of provancheri was later expanded by Wheeler (1903b, p. 231) to include nests with M. brevinodis "in the hummocks of moss (Poly- trichum commune), under stones, bits of wood, etc., in rather damp, grassy bogs."
The ants of three sphagnum bogs in Livingston and Washtenaw counties, Michigan, have been under study for the last four years. The occurrence of several species



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

2 Psyche [March
of Mwmica in various plant communities of the bog sere has been noted, including M. brevinodis and M. fracti- cornis Emery. In spite of intensive observations on ap-
proximately 300 Myrmica colonies, no nests of provancheri have been found.
On the morning of July 22, 1955, several hours were spent in Mud Lake Bog, Section 7, Munro Township, Cheboygan County, Michigan, searching for nests of M. fracticornis. Colonies were found in an immature leather- leaf community, which was characterized by a continuous sphagnum surface and numerous small clumps of shrubs and small trees, composed largely of leatherleaf, highbush blueberry, black spruce, and tamarack. The remains of some dead coniferous trees indicate that this is probably a disclimax community produced by a fire sometime within the last twenty years.
The hummocks of moss at the base of the south edge of a clump of the trees and shrubs named above contained a populous colony of fracticomis. While this nest was being sampled, several workers of provancheri were dis- cover<ed moving about the galleries and chambers of the nest. Seven provancheri workers were collected and kept alive with a small portion of the fracticornis colony. Other workers of provancheri were carefully watched in order to find the location of their nest. These workers were soon lost, and their nest was not located. Most likely it was somewhere on the periphery of the fracti- cornis nest, and it may have been destroyed or displaced during collecting.
Smith (1951, pp. 821-822) cites records for provancheri and its synonyms from four New England States, Colorado, and Alberta, Canada, and it also occurs in North Dakota (Kannowski, 1956). The present record is the first from Michigan and, together with the North Dakota locality, ties together a previously discontinuous distribution. Cole's record from New Mexico is the only extension to the geographic range of this ant given by Creighton (1950, pp. 279-280). The range of provancheri is blanketed by the ranges of both of its known host species (see Creighton, op. cit., pp. 96 and 100). Therefore, provancheri could



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

19571 Kannowski - Leptothorax provancheri 3 have a much more extensive range than that which is presently known. The rarity and limited distribution of this species seem to be due to three factors: 1) very few areas within its hypothetical range have been studied intensively; 2) provancheri workers may easily be over- looked because of their small size and relatively few num- bers (in comparison with the numbers of the host species) ; 3) because of environmental factors, its range is more restricted than that of its hosts.
The apparent absence of provancheri in bogs in south- eastern Michigan indicates that the factors governing its distribution are different from those governing the distri- bution of the two host species. The bogs that have been studied in Livingston, Washtenaw, and Cheboygan coun- ties are composed of similar plant communities, and the edaphic conditions are similar. Climatic conditions seem similar except for the extremes of temperature found in the two regions. Summer temperatures in southeastern Michigan are higher than those of Cheboygan County, and these high temperatures occur for longer periods of time. The temperatures in southeastern Michigan may be too high for the proper development of provancheri colonies, although this factor may not be critical in the case of the two species of Myrmica. The presently known range of provancheri strongly suggests an adaptation to regions of cool temperatures.
Myrmica fracticornis has not previously been recorded as the host of any inquilinous ant, probably as the result of insufficient study of ants in the moist environments of northeastern North America. Additional records should turn up in the future. It also seems probable that other species of Myrmica may be found as hosts of provancheri. Seven provancheri workers were kept for about two months in an artificial nest with a small fragment of the fracticomis colony, including one queen, four alate females, three males, about 50 workers, and a small quantity of larvae and pupae. Random observations of the mixed nest during this time showed that the provancheri workers were accepted by the fracticornis colony; no evidence of hostility between the two groups was ever observed. The two



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

4 Psyche [March
groups utilized separate areas for nest sites, but each permitted the other within its own area. The provancheri workers were seen to "shampoo" the backs and heads of fracticornis workers and females and to receive regurgi- tated food in return just as Wheeler (1901) had observed to occur between provancheri and brevinodis. The pro- vancheri and fracticornis workers were also observed - feeding together on honey, syrup, and water that was placed in the chambers, but only the fracticornis workers were seen to feed upon the bodies of freshly killed insects (roaches, flies, lacewing-flies, and collembolans) that were also introduced into the nest.
From the above observations it seems evident that pro- vancheri is in an early stage of social parasitism as in- dicated by its ability to live independently in part of its range, whereas in other parts it requires the presence of Myrmica nests. In those areas where it lives as an in- quiline it is also probable that the colony-founding female seeks first a suitable environment (one that is both moist and cool), and, once there, seeks a Myrmica nest. In Michigan bogs the choice of Myrmica nests in the open mat zone is largely restricted to brevinodis and fracti- c0rnis.l In other areas (North Dakota, for instance) Myrmica brevispinosa Wheeler may occur in the same or similar environments as those occupied by brevinodis and fracticornis.
The rarity of provamheri and fracticornis combinations may indicate that fracticornis tolerates the inquilines less frequently than brevinodis does. The sim- ilarity of the behavior of fracticornis and brevinodis in response to the "shampooing" by the provancheri workers suggests that this behavior pattern may be common to other more closely related species of Myrmica. A third species of Myrmica of uncertain identity is also present in southeastern Michigan bogs.
COLE, A. C.
1954. Studies of New Mexico ants. X. The genus Leptothorax (Hymenoptera : Formicidae). Jour. Tenn. Acad. Sci. 29 (3) : 240-241.



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

19571 Kannowski - Leptothorax provancheri 5 CREIGHTON, W. S.
1950. The ants of North America. Bull. Mus. Comp. Zool. Harvard Coll. 104: 1-585.
KANNOWSKI, P. B.
1956. The ants of Ramsey County, North Dakota. Amer. Midi. Nat. 56 (I) : 168-185.
SMITH, M. R.
1951. Family Formicidae in: Hymenoptera of America North of Mexico. U.S.D.A. Agric. Monog. No. 2. pp. 778-875. WHEELER, W. M.
1901.
The compound and mixed nests of American ants. I. Observa- tions on a new guest ant. Amer. Nat. 35: 431-448. 1903a. Ethological observations on an American ant (Leptothorax emersoni Wheeler). Arch. Psycol. Neurol. 2 : 1-31. 1903b. A revision of the North American ants of the genus Lepto- thorax Mayr. Proc. Acad. Nat. Sci. Phila. 55: 215-260. THE ARMY ANT AENICTUS EXIGUUS CLARK A SYNONYM. The description and figure of Aenictus exiguus Clark, 1934, Mem. Nat. Mus. Vict., Melbourne, 8 :21, pi. 2, fig. 1, worker (type loc. : Cairns district, northern Queensland) agree well enough with samples from Queensland, New South Wales, and New Guinea of Aenictus turneri Forel, 1900, Ann. Soc. Ent. Belg., 44: 75, worker (type loc.: Mackay, Queensland), except for the low measurement ("1.7 mm.") given by Clark for his types. This measure- ment, like others that have been checked from dark's ant descriptions, appears to be excessively small, even for such a size-variable species as turneri. Particular similar- ities in the critical characters of head and mandible form, and shape of propodeum and ventral process of petiole, all indicate that Ae. exiguus must be considered a new synonym of Ae. turner!. Brown, 1952, Psyche, 58 : 123, had already placed Ae. deuqueti Crawley as a synonym of Ae. turner! after examining type material. - W. L. BROWN, JR., Museum of Comparative Zoology.




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