Proceratium pergandei

An unusual Proceratium in that it has been collected many times. This is a forest species that nests in rotten wood that is touching or partially in the ground (logs, stumps), under rocks and in the soil.

Identification
A member of the pergandei clade. Differing from its sister species Proceratium chickasaw by the postpetiole densely and strongly granulate instead of superficially granulate, by the shorter gaster (IGR 0.26-0.31 instead of 0.24-0.26), and by the gaster with denser and shorter hairs. (Baroni Urbani and de Andrade 2003)

Within the United States, the low rounded petiole distinguishes this species from Proceratium croceum, Proceratium crassicorne, Proceratium silaceum and Proceratium californicum. The antennal scapes when laid back against the head do not reach the posterior margin of the head, unlike Proceratium compitale and Proceratium creek. The second tergite does not protrude strongly rearward as in Proceratium chickasaw.

Distribution
United States: New York, Ohio, Massachusetts, Pennsylvania, New Jersey, Maryland, Washington D.C, Iowa, Colorado, Kansas, Virginia, Oklahoma, Arkansas, Tennessee, North Carolina, South Carolina, Alabama, Mississippi, Georgia, Texas, Louisiana, Florida. Other state records resulting from the literature but not verified by ourselves are not included. Most of them, however, appear perfectly plausible. (Baroni Urbani and de Andrade 2003)

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Biology
Nests have been found under stones (Wesson and Wesson 1940) and in dead wood (Brown 1980). In the sandy soils of Florida it is probable that the nests are normally subterranean, as the species is known almost entirely from strays taken in leaf litter. A small colony (8 specimens) was found in a rotten pine stump below the surface of the ground. Paul Skelley collected several specimens from traps set up in burrow systems of pocket gophers (Geomys pinetis). Wesson and Wesson offered living and dead insects to a captive colony, but the only food accepted were the contents of the gasters of a few dead ants. Brown (1980) found a colony feeding on and storing spider eggs in a nest in rotten wood.

Wesson & Wesson (1940) kept under observation a colony of P. pergandei from Jackson (Ohio) comprising 1 gyne, 11 workers and 8 males. After many attempts to feed the colony on different types of insect food, the authors suggest that these ants may live on dead or dying ants at least in part. Talbot (1957) found in St. Charles (Missouri) a supposedly complete colony of Proceratium pergandei comprising 1 gyne, 13 workers and 13 larvae. (Baroni Urbani and de Andrade 2003)

Nomenclature

 *  pergandei. Sysphincta pergandei Emery, 1895c: 264, pl. 8, fig. 4 (w.) U.S.A. Smith, M.R. 1928b: 242 (m.). Baroni Urbani & De Andrade, 2003b: 227 (q.). Combination in Proceratium: Brown, 1958g: 248.

Worker
Baroni Urbani and de Andrade (2003) - Head longer than broad, its sides subparallel in the two anterior thirds and gently converging in the posterior third. Anteromedian part of the clypeus rectangular, strongly protruding anteriorly and with a variably marked inverted Y-shaped carina dorsally. Frontal carinae diverging posteriorly, slightly raised and not very close each other. Lateral expansions of the frontal carinae narrow. Genal carina absent. Gular area not impressed. Eyes small, in small specimens they are represented by a dark dot below the integument and in larger specimens by a dot of about 8 weakly salient ommatidia. Eyes placed on the mid line of the head. First funicular joint 1/5 longer than broad. Anterior ocellus sometimes present. Funicular joints 2-10 as broad as long or slightly broader than long. Last funicular joint about as long as the sum of joints 8-10. Scapes much short of the vertexal margin and gently thickening distally. Antenna1 torulus behind the lateral border of the clypeus. Masticatory margin of the mandibles with 4-5 denticles before the pointed apical tooth. Palp formula 4,3.

Mesosoma as long as or slightly longer than the maximum head length (mandibles included). Promesopleural and meso-metapleural sutures impressed ventrally only. Basal and declivous faces of the propodeum separate by a carina sometimes interrupted medially. Declivous face of the propodeum with a relatively broad semitransparent lamella sometimes denticulate on each side between the basal and declivous faces. Propodeal spiracle round and above mid height in lateral view.

Petiole convex in profile, with the sides diverging on the anterior fourth and strongly convex posteriorly in dorsal view. Anterior border of the petiole straight or gently concave and variably carinate, the carina sometimes forming a denticle on each side. Ventral process of the petiole lamelliform, triangular and pointed. Postpetiole anteriorly as broad as or slightly broader than the petiole; its sides diverging, sometimes gently convex on the posterior half or on the whole sides. Postpetiolar sternite anteromedially with a marked subtriangular projection. Posterior half of the postpetiolar sternite convex. Constriction between postpetiole and first gastral segment impressed. First gastral tergite variably salient on the curvature. Remaining gastral tergites and sternites curved ventrally.

Legs slender but not very elongate. All tibiae with a pectinate spur. Spurs of fore legs with basal spine. Fore basitarsi longer than the mid ones. Hind basitarsi about 1/5 shorter than hind tibiae. Second tarsomere of hind leg longer than the pretarsus. Pretarsal claws simple. Arolia absent.

Queen
Baroni Urbani and de Andrade (2003) - (previously undescribed). Differing from the worker in the following details: eyes about 1/6 of the head length and with well defined ommatidia. Ocular pilosity present. Ocelli present. Scapes slightly shorter.

Mesosoma robust. Scutellum large, longer than the basal face of the propodeum; its sides gently converging into a convex posterior border. Metanotum sometimes with a small denticle. Median length of the basal face of the propodeum about half of the declivous face. Propodeal lamellae normally broad or narrower in some specimens.

Petiole slightly broader than long. Postpetiole anteriorly slightly broader than the petiole and with convex sides.

Fore wings of our type 1, hind wings of our type 2 as defined in the description of the genus.

Measurements in mm and Indices: TL 4.87-5.10; HL 0.99-1.00; HW 0.86-0.88; EL 0.17-0.18; SL 0.66-0.67; WL 1.36- 1.40; PeL 0.38-0.39; PeW 0.41-0.43; HFeL 0.82-0.86; HTiL 0.70-0.72; HBaL 0.58-0.62; LS4 0.39; LT4 1.32; CI 86.0-88.8; SI 66.7-67.0; IGR 0.30.

Sculpture. Head, mesosoma, petiole and postpetiole granulopunctate, the granulation more marked on the mesosoma, petiole and postpetiole. Gaster variably smooth and granulopunctate, the granulation variably marked.

Body covered by hairs of three main types: (1) short, dense, subdecumbent on the whole body, sparse and suberect on the funicular joints; (2) longer than type (1), sparse and sitberect on the whole body, absent on the funiculi; (3) shorter than hair type (1), dense and decumbent on the funicular joints only. In addition the funicular joints bear whitish, thick, appressed, short, sparse hairs, and the scapes with sparse hairs similar to type (2) but shorter.

Colour light brown.

Measurements in mm and Indices: TL 3.58-4.68; HL 0.81-1.00; HW 0.69-0.87; EL 0.03-0.06; SL 0.54-0.68; WL 1.00-1.28; PeL 0.32-0.40; PeW 0.32-0.42; HFeL 0.62-0.86; HTiL 0.54-0.75; HBaL 0.43-0.60; LS4 0.27-0.38; LT4 0.89-1.22; CI 85.2-87.0; SI 66.7-68.7; IGR 0.26-0.31.

Male
Baroni Urbani and de Andrade (2003) - Head slightly broader than long. Vertex in dorsal view convex. Vertexal margin not carinate. Clypeus dorso-medially convex and with weakly convex or almost straight anterior border. Frontal carinae thin, low, diverging posteriorly. Frontal area with sulcus. Ocelli large. Compound eyes large and placed mostly on the anterior part of the head sides. Scapes reaching the anterior ocellus. First funicular joint about 2/3 of the length of the second joint. Joints 2-11 longer than broad. Last funicular joint slightly shorter or as long as the sum of joints 10-11. Mandibles edentate or with a minute denticle close to the base and only with a pointed apical tooth. Palp formula 5,3.

Mesosoma robust. Pronotum and anterior third of mesonotum almost perpendicular to the posterior two thirds of the mesonotum. Posterior two thirds of mesonotum nearly flat. Parapsidal furrows marked. Scutellum as high as the mesonotum; posterior border of scutellum round. Basal and declivous faces of the propodeum distinct. Sides of the basal face of the propodeum gently converging posteriorly and separate from the declivous face by a carina. Declivous face of propodeum laterally carinate. Metanotum with a median spine like projection. Propodeal lobes round. Propodeal spiracles small.

Petiole declivous in the anterior third and convex in the two posterior thirds in profile. Sides of the petiole parallel in the anterior third and convex in the two posterior thirds in dorsal view. Anterior border of the petiole concave and carinate. Subpetiolar process small, subtriangular and lamelliform. Postpetiole anteriorly slightly broader than the petiole; postpetiolar sides diverging or slightly convex posteriorly. Anterior border of the postpetiolar sternite with a superficial triangular "lip". Posterior half of the postpetiolar sternite gently convex. Gastral tergite I round. Gastral sternite I large. Remaining gastral tergites and sternites slightly curved ventrally.

Legs as in the worker but more elongate.

Fore wings of our type 1, hind wings of our type 2 as defined in the description of the genus.

Sculpture. Head, mesosoma, petiole and postpetiole punctate and covered by small, foveae-like, dense reticulation, the reticulation less impressed the ventral part of the head, on the upper mesopleurae and on the postpetiole, large on the basal face of the propodeum, irregular on the metapleurae. Declivous face of the propodeum smooth and with striae converging posteriorly. Caster smooth and with sparse, minute piligerous foveae. Legs superficially smooth and minutely granulate.

Pilosity as in the worker.

Colour. Dark brown to black with lighter antennae and legs.

Measurements in mm and Indices: TL 3.67-4.06; HL 0.64-0.69; HW 0.69-0.74; EL 0.35-0.38; SL 0.38-44; WL 1.36-1.48; PeL 0.34-0.38; PeW 0.33-0.36; HFeL 0.73-0.84; HTiL 0.64-0.70; HBaL 0.54-0.63; LS4 0.44-0.51; LT4 0.78-0.92; CI 107.2-108.8; SI 59.3-64.7; IGR 0.55-0.56.

Type Material
Baroni Urbani and de Andrade (2003) - Type locality: Beatty (Pennsylvania) and Washington D.C., USA. Type material: one syntype worker labeled: "Beatty, Pa, no. 175, Typus" in MCSN, one syntype worker labeled: "Washgtn, June 5 DC, Typus, Sysphincta pergandei Em" in, one syntype worker labeled: "Washgnt, 6, 14 DC, no. 175, cotypus, S. pergandei Em" in , all examined.