Stenamma schmittii

Smith (1957) reports: It appears Stenamma schmittii is primarily a woodland loving form which is capable of living in fairly dry to moist habitats. Colonies are usually found nesting in the soil beneath stones, logs, rotten wood, moss, leaf mould, and other debris and are often difficult to find. The species has been collected at altitudes ranging from only a few hundred feet to approximately 5,000 feet. Mary Talbot has excavated a number of colonies in the Droste Woodsin St. Charles County, Missouri. She has found colonies apparently containing from only one to four chambers and at depths of 5 to 15 inches. It appears that there is only a single mother queen per colony. The largest colony examined, on September 29, 1950, consisted of four chambers at depths of 5, 6, 7, and 10 inches. The colony contained 310 workers, 31 alate females and 35 males, 9 eggs, and 67 larvae. No pupae were seen, nor was the mother queen found. Miss Talbot did not think that this was a hibernating colony. Her general observations on Stenamma schmittii indicate that alate females and males are produced in late summer, by some colonies at least, and that these castes overwinter in the parental nest until the following spring. The most common if not the only immature stage in which the ant overwinters is the larval.

Talbot (1957) added additional information from a study where she excavated soil during the cooler months of the year, in a Missouri woodland, on order to survey ant nests. Stenamma schmitti was slightly less common, being collected seven times. Males and females were found in September and October. Evidently flight is late in this species. Chambers were well defined and slightly larger than those of the previous species. Four colonies had one chamber, while the remaining three occupied two, three, and four chambers respectively. The depth of chambers ranged from five to fifteen inches, and the mean was 10.5 inches. Complete colonies were collected only four times; these gave a mean population of 227, of which 121 were workers.

Smtih (1957) also provides a communication from Brown regarding schmitti: ""The workers appear to have no set way of approaching the collembolans, but merely rush their prospective prey with mandibles opened wide. The collembolans usually manage to escape if attacked in an open space between the leaves in my jar, but if caught in a crevice or pocket, they have little chance of getting away. The attack by the ants is clumsy and hurried, in contrast to the finesse displayed by the collembola catching dacetines, and there Seems little doubt that springtails form only' a part of their diet. Use of the sting has not yet been observed but the rapid immobilization of the colIembolan renders stinging a possibility to be considered when conditions of observations can be made more favorable than they were in the cases studied."

Identification
Stenamma schmitti is a highly variable species in many respects. Such variations especially apply to the size of the eye and the number of ommatidia in its greatest diameter; the number (usually 4-6) and size of the basal teeth of the mandibles; the size and shape of the mesoepinotal impression, size of the epinotal spines, shape and proportions of the petiolar and postpetiolar nodes. The color and sculpture of the body are very variabLe as is also the degree of development of the longitudinal rugulae and shagreening on the first segment of the gaster.

The worker can be distinguished by the size and structure of the eye; the nature and appearance of the sculpturing of the body; the usually well developed and very distinct mesoepinotal impression; shape and proportions of the petiolar and postpetiolar nodes. The worker is most apt to be confused with that of Stenamma imparis. It differs especially in the smaller eye, the larger and more coarsely sculptured and also more opaque body.

Smith 1957

Range
This species has been recorded from Maine to North Carolina and west to Minnesota and Missouri

Smith 1957

It is also known from Quebec.

Taxonomy
Stenamma brevicorne subsp. schmitti Wheeler, W.M. 1903d: 167 (diagnosis in key) (w.) U.S.A. Smith, M.R. 1957b: 144 (q.m.). Raised to species: Creighton, 1950a: 138.

Type Material
American Museum of Natural History, Museum of Comparative Zoology at Harvard College

Type Locality Information
St. Vincent, Pennsylvania, 1-1/2 miles SW of Latrobe in Westmoreland County

Etymology
Patronym. Described from workers collected by P. J. Schmitt.