Leptogenys manni

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Leptogenys manni
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species: L. manni
Binomial name
Leptogenys manni
Wheeler, W.M., 1923

Leptogenys manni casent0104002 profile 1.jpg

Leptogenys manni casent0104002 dorsal 1.jpg

Specimen labels

Prey records for L. manni are mostly of the isopod Porcellionides virgatus (Budde-Lund), with occasional Armadillidium. Males are taken mostly from the months of May to October, and workers are mostly found during the spring months beneath stones and logs (Trager & Johnson 1988).

Identification

Lattke (2011) - A member of the elongata species group. Head sub-rectangular in full-face view, lateral cephalic margin broadly convex; posterior cephalic margin convex; lateral clypeal process narrow, its outline forming obtuse angle with outline of median process; mesosternum and mesopleuron joined by smooth curve, feeble carinae present anterad with weak anterior angle; posterolateral area of propodeal declivity rounded, without angle or lobe.

Keys including this Species

Distribution

This species is mostly known from throughout Florida, and is probably endemic to the state. Specimens labeled as from Georgia constitute a single series and lack a date, though the state of the label suggests the early 1900’s. L. manni is now known to range into northern Florida, but over 300 kilometers separate Decatur from the nearest L. manni collection sites in Florida. The Georgia locality is a possibility but needs corroboration. Similarly, Creighton (1950: 50) called into question reports of L. manni north of Florida. (Lattke 2011)

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The following information is from Trager and Johnson (1988). Colonies and foraging workers are most frequently found in spring in mesic woodlands where limestone is near the surface. Males can be found in traps from May into October. Midden piles outside nests indicate that the most common prey in Florida is the native isopod Porcellionides virgatus, but introduced species of Armadillidium are also taken. In the lab, L. manni captures Porcellionides more readily than Armadillidium. Larvae are placed on the dead or paralyzed isopods.

Castes

Worker

Male

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • manni. Leptogenys (Lobopelta) elongata subsp. manni Wheeler, W.M. 1923d: 14 (w.) U.S.A. Trager & Johnson, 1988: 31 (q.m.). Raised to species: Trager & Johnson, 1988: 31. See also: Lattke, 2011: 161.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Lattke (2011) - Wheeler (1923) recognized L. manni as a subspecies of Leptogenys elongata on account of a more slender head, the anterior petiolar margin meeting more evenly the dorsal margin in lateral view (not as truncate as in L. elongata), and the presence of cuticular opalescence. Trager & Johnson (1988) recognize L. manni as a distinct species from L. elongata due to differences in the texture of cuticular sculpture, color, male genitalia, distribution, and natural history. During the course of this study the aforementioned characters were corroborated and additional traits found to support species rank for L. manni. The median clypeal lobe is relatively more slender in L. manni, with the angle of contact between median lobe and lateral clypeal lobe more noticeable than in L. elongata. L. manni has the mandibular dorsal surface more smooth and shining, and the anteroventral mesopleural carina very weak to non-existent compared with L. elongata. This carina is well developed in L. elongata, and sharply defines the limit between the mesosternum and mesopleuron, forming an anterior lobe that extends mesad as a crest which delimits a narrow, transverse area along the anterior mesosternum. In L. manni the modest anterior angle of the carina does not extend elsewhere. L. elongata has a low angular projection on the propodeal declivity next to the bulla, whilst such a projection is lacking in L. manni, sometimes present as a weak convexity. Trager & Johnson (1988: 34) found significant differences between the two species in the male genitalia: the paramere in L. manni has the apex ending in an acute, blunt angle but in L. elongata it is a rounded lobe; the aedeagus in L. elongata ends in a rounded lobe, but in L. manni it forms a narrow process which ends in a small bifurcation. L. manni males have an apparently thicker cuticle, with impressed lines on the mesoscutum deeper and wider than in L. elongata, besides ferruginous colors that make them very apparent. The posterolateral lobes of the pronotum curve away from the mesosoma, whilst they tend to be closely adhered to the mesosoma in most L. elongata males examined, with some Mexican specimens presenting slight separation. The ocelli in L. elongata males are relatively larger than in L. manni, with the diameter of the median ocellus approximately half the distance between the lateral ocellus and the compound eye, this distance being greater or equal to the diameter of the median ocellus in L. manni.

Description

Worker

Lattke (2011) - Metrics (n = 6): HL 1.44-1.52; HW 0.91-0.99; ML 0.68-0.76; EL 0.30-0.33; SL 1.47-1.62; PW 0.78-0.86; WL 2.18-2.35; PH 0.76-0.86; PL 0.68-0.73; DPW 0.46-0.53 mm. CI 0.60-0.65; MI 0.69-0.81; OI 0.32-0.36; SI 1.61-1.69; LPI 1.10-1.21; DPI 0.67-0.75.

Head subrectangular in full-face view, lateral cephalic margin broadly convex; posterior cephalic margin convex; median clypeal process tapers to rounded, lamellate apex, apex with two long hairs, no setae; lateral process narrow, its outline forming obtuse angle with outline of median process. Eye broadly convex, situated slightly dorsad at mid-length, occupies under one-third of lateral cephalic margin. Cephalic dorsum densely punctate, distance between each depression less than or equal to their respective diameter, punctae not sharply defined but gradually depressed, usually more on one side, shining; longitudinal to oblique striae present between eye and antennal insertion; longitudinal sulcus stretches from between frontal carinae to mid-eye height. Scape mostly smooth and shining with fine punctulae, abundant appressed pilosity and occasional decumbent to subdecumbent hairs, scape extends beyond posterior cephalic margin by one-third length its length; third antennal segment slightly 3 x longer than apical width, third antennal segment more than half length of second; each funicular segment wider apicad than basad. Mandible triangular, shutting tight against clypeus, mostly smooth and shining with sparse punctae; chewing border edentate, corner with blunt angle.

Mesosoma with broad and deep metanotal groove in lateral view that separates broadly convex promesonotal margin and straight to weakly convex dorsal propodeal margin; lateral pronotal sculpture mostly smooth and shining with minute punctulae, posteriorly longitudinally striate; abundant parallel transverse striae on mesopleuron; metapleuron with transverse to longitudinal parallel striae; lateral propodeal face punctate to striate, striae stronger towards declivity. Mesometapleural suture well impressed; metapleural-propodeal suture not impressed or appearing as brief narrow ledge just anterad of propodeal spiracle; propodeal spiracle elongate, opening directed posteriorly; disc of pronotum mostly smooth and shining with sparse punctulae, punctulae denser anterolaterally, striae present along anterior margin; mesonotum transversely striate punctate, longer than wide; propodeal dorsum rugulose to transversely striate; declivitous face transversely striate, rounding to lateral propodeal face, not separated by sharp ridge; prosternum transversely striate; mesosternum and mesopleuron joined by smooth curve, feeble carinae present anterad with weak anterior angle; metanotal groove straight to convex, smooth.

Petiole subquadrate in lateral view, higher posterad than anterad; anterior margin more than one-half height of posterior margin, anterior margin straight, dorsal margin convex, posterior margin weakly convex to straight. Subpetiolar process sub-rectangular to rounded in lateral view, with concave posterior margin. Node elongate in dorsal view; anterior margin convex, more than half width of posterior margin. Posterior face rounds to lateral face, sometimes separated ventrad by low ridge; lateral node face with longitudinal striae dorsad, ventrad tending to smooth with weak undulations and rugosities; dorsum with transverse to oblique low striae. Anterior postpetiolar margin broadly convex in lateral view, curving onto dorsal margin; gaster smooth and shining, constriction between abdominal segments III and IV well marked; procoxae with some low rugosities, mostly smooth. Body with abundant decumbent pilosity and scattered standing-suberect hairs. Head, mesosoma node and most of gaster ferruginous or orange, some specimens with traces of blue or purple opalescence; antenna, mandibles, legs and apex of gaster light ferruginous. Meso and metatibial apex each with single external seta.

Queen

Lattke (2011) - None examined. Trager & Johnson (1988) report the queen as the usual ergatoid with a larger gaster and lower, subtriangular petiole profile compared with the worker.

Male

Lattke (2011) - Not measured. Head mostly shining with shallow punctures, transverse striae present anterad of antennal fossae; clypeus punctate. Pronotum mostly punctate, punctae denser medially than laterally; anterior mesonotum separated by gap from posterior pronotum. Scutum with well-impressed medial line, in dorsal view extending anterad from anterior base of scutellum, between tegulae bifurcating into notauli; medial line and notauli scrobiculate; parapsidal line impressed from anterior base of axilla until almost touching notaulus; impressed lines with ferruginous staining along crests of scrobiculae. Mesonotum and mesopleuron mostly smooth and shining with punctulae; metapeluron, propodeum mostly with low rugulae.

Type Material

Syntype workers: United States, Florida, Dunedin (McGregor) (Museum of Comparative Zoology) [examined].

References