Overbeckia jambiensis 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 : 569-570

Overbeckia jambiensis Klimes , sp. nov.

( Fig. 4 )

Etymology

Named after the Jambi Province on Sumatra Island ( Indonesia) where the type specimen was collected by J. Drescher in the lowland rainforest of Bukit Duabelas National Park (EFForTS project core plot BF2, see Drescher et al. 2016).

Material examined

Holotype: Worker ( MZB): BF2.2/ 7.x.2013 / wet season/canopy fogging/lowland forest / Bukit Duabelas National Park / 01°58′54.2″S, 102°45′02.3″E /leg. J. Drescher (det. R. Nazarreta, P. Klimes)

Paratype: Worker ( ZMHB):same data as above but marked as paratype.

Diagnosis

Overbeckia jambiensis workers are the hairiest of the Overbeckia species, with numerous conspicuous erect hairs present on dorsum of petiole, thorax, and also dorsally and ventrally on the head, abdomen and scape; head integument without punctation and with fine lineation; cuticle covered with sparse, short, appressed hairs that are less numerous but longer than in other species and present all over the head except in the area between the eyes and around carinae; integument darker and glossy; frontal carinae less approaching one another anteriorly compared to those of O. subclavata but curvature evenly convex when compared to those of the other species in frontal view ( Fig. 4 d ). Lineation present on whole lateral sides of mesosoma, including upper part of frontal coxae and the areas above metathoracic spiracle.

Description of worker

Morphometrics. Holotype ‘BF2.2.’ (one paratype): HL 1.37 (1.29), HW 1.29 (1.30), IOD 0.94 (0.96), CL 0.24 (0.22), CW 0.53 (0.54), ML 0.55 (0.55), EL 0.40 (0.40), EW 0.30 (0.31), FCDp 0.42 (0.43), FCDa 0.31 (0.31), SL 1.30 (1.27), SWmax 0.16 (0.16), SWmin 0.08 (0.08), WL 1.94 (1.94), PW 0.96 (0.97), HFL 1.30 (N.A.), HFT 0.29 (N.A.), HTL 1.24 (N.A.), PetW 0.45 (0.44), PetL 0.24 (0.22), FCDI 137 (141), CI 94 (101), SI 101 (98), MI 40 (42).

Head. General morphology as for the genus (see above). Frontal carinae less approaching one another anteriorly (FCDI = 137) and with convex curvature laterally ( Fig. 4 d ).

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

Pilosity. Tiny appressed hairs (approximately twice the length of ommatidium) present only sparsely over the head and mesosoma; numerous relatively long erect hairs (length ≥ SW) present on the clypeus and head, and all over abdomen; these longer hairs also present on genae and occipital corners of the head and on frons, surpassing the head margin in frontal view ( Fig. 4 b ); scape with relatively long hairs of both appressed and erect type, the erect hairs not limited to the apical tip but present along most of the scape ( Fig. 4 b ). Approximately eight erect hairs growing dorsally from apical margin of petiole.

Sculpture. Fine shallow lines, joining each other to a cell formation over the glossy cuticle of the head ( Fig. 4 b, d ). These lines also present dorsolaterally on mesosoma; the lineation very soft and rather curved, except the lateral sites of mesosoma below metathoracic spiracle and towards coxae and on propodeum, where lines are somewhat deeper and straight ( Fig. 4 a ); soft lineation also present on frontal coxae and petiole.

Colouration. Head, thorax and scape of rather glossy metallic appearance and black, except at scape apex where lighter brown; petiole, abdomen, apical parts of femurs and tibiae brown; tarsi, apex of funiculus and palps brown; femurs pale yellow near the joints; trochanters and mid and hind coxae pale yellow ( Fig. 4 a, c ).

Description of male and queen

None (no material)

Remarks

Body size is somewhat larger on average than in the other two Overbeckia species but due to the availability of only two specimens, assessing whether body size is significantly larger is difficult (the size is comparable to the largest workers measured from series of O. papuana ).

Figures

Fig. 4. Overbeckia jambiensis sp. nov. holotype (worker) and lateral (a), frontal (b) and dorsal (c) views. Detail of head sculpture and shape of frontal carinae (d). Note that the right antenna has been glued into the antennal socket.