Overbeckia papuana Klimes, 2022

Klimeš, Petr, Drescher, Jochen, Buchori, Damayanti, Hidayat, Purnama, Nazarreta, Rizky, Potocký, Pavel, Rimandai, Maling, Scheu, Stefan & Matos-Maraví, Pável, 2022, Uncovering cryptic diversity in the enigmatic ant genus Overbeckia and insights into the phylogeny of Camponotini (Hymenoptera: Formicidae: Formicinae), Invertebrate Systematics 36 (6), pp. 277-288 : 570-571

Overbeckia papuana Klimes , sp. nov.

( Fig. 5 , 6 )

Etymology

Dedicated to all Papua New Guineans, the nation of the country from which the type and nest series were collected ( Papua New Guinea).

Material examined

Holotype. Worker ( ZMHB): Morphospecies ‘ CAMP021 ’/Acc.N. ‘HP0177’/ Tree number code ‘WS4D0868’/Secondary forest/ Wanang village / Madang province / Papua New Guinea / 8.iii.2007 / 05°14′S, 145°11′E /leg. M. Rimandai.

Paratypes. Five workers (1w ZMHB, 1w IECA, 2w NAIC, 1w MZB), one male ( ZMHB), one queen without wings ( ZMHB): From the same nest series as holotype (the same data).

Additional material examined. Papua New Guinea: Other 30 workers and 2 males, including brood, kept in one vial with ethanol in IECA, all from the same nest as the type specimens (same data). Australia (photos): 1 worker ( SAMA): ‘ Camponotus ’/Cairns NQ/on tree/ Parkland/ 2.viii.1975 /leg. B. B. Lowery (frontal and lateral photo on p. 115 in McArthur (2012) and A. McArthur, pers. comm. for coll. information; previously misidentified by the original author for Camponotus janeti ). 3 workers ( WAM): CASENT0872736, CASENT0872753, CASENT0872754 (AntWeb codes; ‘ Overbeckia wam01’): Queensland / Mossman/ 18.ix.2002 /leg, R. Jordan /nest in dead twig in living tree behind sugar mill (thicket near Mossman R.)/det. B. E. Heterick, ii.2018. 1 worker ( CASC): CASENT0887749 (AntWeb code; ‘ Overbeckia au01’): Queensland /Mt Peters/ 1. v. 2014 /leg, M. Collis/ det. A. Andersen 30.xi.2020. Australia (physical specimen): 1 worker ( ZMHB): n#15720/ AUST Qld/Captain Billy Landing/rainforest, ex. dead hanging twig/ 11°38′S, 142°51′E /leg. P. Ward (the same collection series as CASENT0882197 at AntWeb; ‘ Overbeckia au01’).

Diagnosis

General appearance of worker and queen as in O. subclavata , but hairier on the head, with erect hairs on dorsum of petiole, thorax and abdomen; a few hairs also present on distal part of scape. Head integument less punctate than in O. subclavata , with many short-erect hairs extending past head margins in frontal view; tiny appressed hairs in high densities all over the head including genae; frontal carinae significantly approaching one another anteriorly (FCDI> 190) ( Fig. 5 d ).

Description of worker

Morphometrics. Holotype, ‘HP0177’ nest series (five paratypes; total N = 6, min.–max): HL 1.08 (1.04–1.41), HW 1.10 (1.05–1.43), IOD 0.82 (0.79–1.10), CL 0.17 (0.14–0.23), CW 0.41 (0.39–0.55), ML 0.44 (0.36–0.57), EL 0.28 (0.26–0.34), EW 0.21 (0.19–0.27), FCDp 0.37 (0.35–0.52), FCDa 0.18 (0.15–0.27), SL 1.05 (1.02–1.24), SWmax 0.14 (0.12–0.18), SWmin 0.06 (0.06–0.09), WL 1.58 (1.52–2.02), PW 0.77 (0.69–1.03), HFL 1.09 (0.92–1.24), HFT 0.24 (0.24–0.30), HTL 0.94 (0.82–1.05), PetW 0.39 (0.37–0.47), PetL 0.17 (0.17–0.24), FCDI 208 (193–236), CI 102 (99–105), SI 95 (87–101), MI 40 (30–43).

Head. General morphology as for the genus (see above). Frontal carinae relatively more approaching one another anteriorly above the clypeal margin compared to those of the other species (FCDI = 208), with rather straight carinae curvature all along (only slightly convex laterally adjacent to the antennal sockets at frontal view; Fig. 5 d ).

Mesosoma and metasoma. As for the genus (see above).

Pilosity. Tiny appressed hairs (approximately twice the length of ommatidium or smaller) present in high densities over the head, mesosoma and abdomen; relatively long erect hairs (length ≥ SWmin) present on clypeus, head integument and all over abdomen; these longer hairs are also present on genae and occipital corners of the head and on frons (extending past head margins from the frontal view; Fig. 5 b ); scape with relatively short, appressed hairs (as in O. subclavata ), with a few erect hairs not limited to the apex but present ventrally along the anterior half of the scape. These hairs shorter and less numerous than in O. jambiensis ( Fig. 5 b ). Approximately six erect hairs growing dorsally from apical margin of petiole.

Sculpture. Less dotted, rather covered by short lines joining each other to a cell formation with fine punctation over the glossy cuticle of the head ( Fig. 5 d ) and mesosoma dorsolaterally, with most of these cells like pits at smaller (<80×) magnification ( Fig. 5 b, c ). Lateral sites of thorax with soft lineation below mesothoracic spiracle towards mid and hind coxa. The lineation is also present on frontal coxa and petiole, but smoother.

Colouration. Head, mesosoma and frontal coxa black; scape dark brown except at apex, where lighter brown; funiculus of antennae brown except the lighter apex; petiole dark brown; abdomen and hind tibiae brown, remaining appendages rather light brown, with mid and hind coxae, trochanters and palps pale yellow ( Fig. 5 a, c ).

Description of queen

Morphometrics. Paratype ‘HP0177’ nest series: HL 1.56, HW 1.57, IOD 1.22, CL 0.32, CW 0.59, ML 0.63, EL 0.49, EW 0.37, FCDp 0.50, FCDa 0.24, SL 1.23, SWmax 0.16, SWmin 0.09, WL 2.51, PW 1.14, HFL 1.22, HFT 0.31, HTL 1.27, PetW 0.55, PetL 0.35, FCDI 208, CI 101, SI 78, MI 40.

Head, mesosoma and metasoma. Similar to O. subclavata , except frontal carinae significantly approaching one another anteriorly (FCDI = 208; Fig. 6 e ).

Pilosity. Tiny appressed hairs on scape surface, with three to four longer erect hairs on the lateral sites of the first half of the scape (hair length ≥1 ocellus); presence of many relatively long, erect hairs on the head (length ≥1 ocellus) on genae, above the eyes and over the occipital corners of the head ( Fig. 6 e ), and on thorax dorsum, apical tip of petiole, and over both ventral and dorsal sites of all five abdominal tergites.

Sculpture. Fine punctation over the head, and on mesosoma dorsum and propodeum; and soft lineation on lateral sites of mesosoma ( Fig. 6 a ).

Colouration. Black head, thorax, petiole and frontal coxae; dark brown abdomen and appendages except middle and hind coxae, trochanters, palps and apical tips of antennae and tarsi that are lighter brown ( Fig. 6 a ).

Description of male

Morphometrics. Paratype ‘HP0177’ nest series: HL 0.84, HW 1.00, IOD 0.66, CL 0.12, CW 0.35, ML 0.31, EL 0.34, EW 0.29, FCDp 0.27, FCDa 0.10, SL 0.67, SWmax 0.10, SWmin 0.06, WL 1.71, PW 0.96, HFL 1.31, HFT 0.18, HTL 0.99, PetW 0.33, PetL 0.21, FCDI 255, CI 119, SI 67, MI 37.

Structures and diagnosis ( Fig. 6 b, d, f ). No apparent large distinction when compared to the male of O. subclavata , except for the following minor differences: The specimen is ~10% larger than the measured male of O. subclavata , but morphological measures otherwise considerably overlapping between the two species’ males. Frontal carinae relatively more approaching one another anteriorly than in O. subclavata , but this difference not as distinct as between the two species’ workers (FCDI = 255 v. 229 in O. subclavata male). The hairs on clypeus more numerous than on clypeus of O. subclavata ; presence of many more small hairs on frons and above ocelli (length near 1/2 of ocellus) over the occipital region ( Fig. 6 f ). These small, dense hairs are also present dorsolaterally on thorax (on mesoscutum and mesoscutellar disc; Fig. 6 b, d ). Colouration as in O. subclavata male.

Remarks

The arboreal nest of O. papuana sp. nov. in Papua New Guinea was collected at 16.4 m in a dead vine growing along the tree trunk of Trichospermum pleiostigma (F. Muell.) Kosterm. (diameter at breast height = 16.3 cm). The nest consisted of less than one hundred workers, with one wingless gyne, three males, and multiple larvae and pupae enclosed in cocoons.

The material from Australia was examined and measured mainly from photographs from the following sources: (i) the book by McArthur (2012), where a worker of Overbeckia was incorrectly assigned to Camponotus janeti (minor worker fits ‘ O. papuana’, whereas major worker presumably fits C. janeti ; there is uncertainty as to whether the two individuals are from different localities and pins or are on a single pin at SAMA); (ii) the photos on AntWeb of the three specimens in Heterick (2019) (see above). The Australian specimens appear to be larger in body size based on the measures from the photos (4 workers measured from photos, WL > 1.95 mm) than the Papua New Guinea ( PNG) nest series (6w measured, WL <1.74). However, we treat these as one species because the Australian single specimen sent by P. Ward for direct examination (n#15720) matches O. papuana types in the body size ( WL = 1.64; Supplementary Table S1 ) and morphology.

Figures

Fig. 5. Overbeckia papuana sp. nov. holotype (worker) and its lateral (a), frontal (b) and dorsal (c) views. Detail of head sculpture and shape of frontal carinae (d).

Fig. 6. Overbeckia papuana sp. nov. paratypes (alates). Queen: lateral (a), dorsal (c) and frontal (e) views; male: lateral (b), dorsal (d) and frontal (f) views. Note that the petiole in queen (a) looks wider and blunter due to being bent to the right site (c).