Odontomachus relictus Deyrup and Cover, 2004

Macgown, Joe A., Boudinot, Brendon, Deyrup, Mark & Sorger, D. Magdalena, 2014, A review of the Nearctic Odontomachus (Hymenoptera: Formicidae: Ponerinae) with a treatment of the males, Zootaxa 3802 (4), pp. 515-552 : 540-543

publication ID	https://doi.org/ 10.11646/zootaxa.3802.4.6
publication LSID	lsid:zoobank.org:pub:4A83AAAE-6F0B-4173-A066-DBBCFBC3BDD
DOI	https://doi.org/10.5281/zenodo.6129414
persistent identifier	https://treatment.plazi.org/id/C66787A5-5B30-FF8D-9AE0-FAE5FF00F994
treatment provided by	Plazi
scientific name	Odontomachus relictus Deyrup and Cover, 2004
status

Treatment

( Figs. 5 View FIGURE 5 , 8 View FIGURE 8 , 20 View FIGURE 20 , 21 View FIGURE 21 , 24 View FIGURE 24 , 25 View FIGURE 25 , 26 View FIGURE 26 )

Odontomachus relictus Deyrup & Cover, 2004: 137 (worker, queen, and male) Florida, USA.

Diagnosis. Very similar to O. clarus , but endemic to Florida; O. relictus has never been reported from west of the Mississippi river. Workers are most similar to O. clarus , but may be separated by the striate basalar lobes ( Fig. 5 View FIGURE 5 A). Workers are further separated from other Nearctic species by the following combination: 1) gastric pubescence sparse; 2) basalar lobes striate; and 3) petiolar node lacking conspicuous, transverse striae. Males are uniquely identified by the following combination: 1) body and head dark brown, antennae yellowish-brown; 2) very large, strongly bulging ocelli, and 3) longitudinally striate mesoscutum. The ninth abdominal sternum is unique, having a very short disc relative to length. Genitalia of O. relictus are most similar to those of O. clarus , but are distinguished by the following character combination: 1) telomere apex very narrowly rounded; 2) penisvalvar apicodorsal lobe broader; 3) apicoventral penisvalvar process shorter, broader (see Fig. 25 View FIGURE 25 ).

Description. Worker: HL 2.00–2.06, HW 1.68–1.80, SL 1.94, EL 0.30–0.40, ML 1.20, WL 2.67–2.68, PTH 0.90, PTL 0.44–0.52 (one MEM specimen measured, other measurements from Deyrup and Cover 2004). Entire body generally shiny except where dulled by dense pubescence; head, mesosoma, and petiole reddish-brown, legs yellowish-brown, and gaster blackish. Head with fine, longitudinal striae covering much of the head in full-face view, striae beginning from frontal lobes and diverging toward posterior corners of head, fading at corners and sides; sides and underside of head lacking sculpture; with numerous, fine, appressed pubescence and scattered elongate erect setae present dorsally. Pronotum with somewhat circular concentric striae that become longitudinal posteriorly, then transverse at posterior margin; appressed pubescence abundant; 5–6 elongate, erect setae present. Mesonotum and propodeum with deep transverse striae; with abundant pubescence present dorsally. Propleuron mostly lacking sculpture, smooth and shiny; mesopleuron with longitudinal striae at dorsal and ventral margins, otherwise smooth and shiny; pubescence mostly lacking. Basalar lobe with coarse striate sculpture. Metasternum lacking paired elongate, spiniform processes between hind coxae. Petiole widest at base, gradually tapering apically to a short spine directed rearward; mostly lacking striae with only faint striae present near base; subpetiolar process rounded triangular; appressed pubescence present anteriorly and laterally, but mostly absent posteriorly. Gaster mostly shiny beneath pubescence, lacking striae or other strong sculpture, but with fine coriaceous sculpture (seen at high magnification); fine, appressed pubescence sparse, spaces between hairs more than the length of a hair; scattered erect, elongate setae present.

Male: HL 0.98–1.07, HW 1.30–1.45, SL 0.22–0.24, EL 0.76, EW 0.50, OL 0.22–0.23, OES 0.13, WL 2.43–2.50, PTH 0.64–0.70, PTL 0.44–0.47, FWL 4.95–5.00 (two MEM specimens measured, other measurements from Deyrup and Cover 2004). Body generally shiny except where obscured by dense pubescence; head and mesosoma brownish-black, petiole and gaster dark reddish-brown to brownish-black, femora and tibiae dark brown, tarsi pale yellowish-brown, and antennae yellowish-brown and contrasting with the dark head. Head, meso- and metasoma with abundant whitish subdecumbent pubescence. Eyes extremely large, maximum diameter of each eye at least 70% of the length of the head in full-face view. Ocelli large, length of each ocellus greater than distance between lateral ocellus and eye margin; in full-face view, lateral ocelli protrude beyond posterior border of head. Mesosoma: pronotum lacking sculpture; mesoscutum with fine transversely arcuate striae anteriorly, striae becoming longitudinal posteriorly; mesoscutellum convex, shiny, with longitudinal striae; propodeum long and low without a declivious posterior face, with fine striae in concentric ovals medially, transversely bisinuate posteriorly, and longitudinal laterally. Mesopleuron with weak to slightly strong transverse striae. Petiole bluntly rounded apically, with rounded triangular subpetiolar process anteriorly; densely pubescent anteriorly and laterally, with reduced pubescence posteriorly. Abdominal sternum IX disc very short, breadth almost three times length; posterior lobe length about twice width. Telomeral apex very narrowly rounded, almost angular; telomere length distinctly greater than height; valviceps ventral apex weakly produced, narrow; valviceps apical margin linear to weakly concave; apicodorsal lobe of valviceps somewhat narrow and short; vertical portion of dorsolateral carina and lateral margin of subapical lamina curving into one another.

Queen: HL 2.15, HW 1.77, EL 0.27, ML 1.20, PTL 0.52, WL 2.75 (measurements from Deyrup and Cover 2004, one individual measured). Structure and color similar to worker, but with presence of ocelli and expanded mesosoma (for flight); pronotum with transverse striae; and mesonotum with longitudinal striae.

Distribution ( Fig. 26 View FIGURE 26 ): Described from Highlands, Polk, Orange, and Citrus Counties in south-central peninsular Florida ( Deyrup and Cover 2004).

Discussion. Odontomachus relictus is endemic to sand ridges in central Florida. It was described from the Lake Wales Ridge, including an outlier site previously thought to be part of the Orlando Ridge, and the Southern Brooksville Ridge, although the latter may be a distinctive allopatric population that deserves taxonomic recognition (Sorger, unpublished genetic data).

Little is known about the habitat requirements and nest structure of O. relictus . This species has been observed to nest in the ground at the base of oak bushes and is often found in places with at least some leaf litter cover. Due to specific habitat preferences or microclimatological needs, O. relictus may be threatened by human development and disturbance. This species is predominately nocturnal. Male flight activity peaks conspicuously during July through October, apparently correlated with moonlight (see Deyrup et al. 1985, where O. relictus is identified as O. clarus ).