Tetramorium cf. kraepelini Forel, 1905

Yamane 1, Seiki, Hosoishi 2, Shingo & Ito 3, Fuminori, 2022, Japanese Tetramorium queens: identification key and species diagnoses (Hymenoptera, Formicidae, Myrmicinae), ZooKeys 1084, pp. 43-64 : 43

Tetramorium cf. kraepelini Forel, 1905

Figs 1i, lp, 2b, 4b, 5b

Queen diagnosis.

Measurements (n = 1): TBL 2.7, HL 0.64, HW 0.58, SL 0.38, EL 0.21, EW 0.16, PtW 0.23, PptW 0.28, CI 90.6, SI 65.5, ELI 32.8. Body yellowish-brown. Frons between frontal carinae with weak longitudinal rugae. Clypeus with some weak longitudinal carinae; anterior margin of clypeus without median notch. Eye large, 2 times as long as distance between anterior margin of eye and mandibular base. Distance between posterior ocelli less than 2.5 × ocellar diameter. Vertex, temple including posterolateral corner of head, dorsum of pronotum puncto-reticulate. Entire mesonotum with dense and longitudinal rugae; dorsum of propodeum longitudinally rugose, continuous to anterior margin of posterior declivity that is weakly transversely striate. Lateral face of pronotum and upper portion of mesopleuron distinctly striate; lower portion of mesopleuron only superficially sculptured and shiny. Petiole with strong carinae on lateral face, superficially sculptured and weakly shiny on dorsum; dorsum of postpetiole smooth and shiny. Gastral tergite 1 basally without carinae, smooth. Antennal scape and mid- and hind-tibiae with erect/suberect hairs.

Caste difference.

Worker measurements (n = 5): TBL 2.0-2.1 (2.1), HL 0.58-0.61 (0.60), HW 0.53-0.55 (0.54), SL 0.35-0.38 (0.36), EL 0.14-0.16 (0.15), EW 0.09-0.10 (0.10), PtW 0.17-0.18 (0.18), PptW 0.19-0.23 (0.22), CI 88.3-90.2 (90), SI 65.5-69.1 (67.3), ELI 23.7-26.2 (25.1). Worker smaller than the queen. In the worker, head more extensively reticulate, leaving area behind clypeus longitudinally rugose. Eye smaller than in the queen, as long as or only slightly longer than distance between anterior eye margin and mandibular base. Eye strongly converging anteriad; in the queen, eye broadly rounded anteriorly. Mesosomal dorsum entirely densely reticulate; in the queen, mesonotum with dense longitudinal striae. In the worker, both petiole and postpetiole dorsum smooth and shiny.

Specimens examined.

C. Ryukyus: 1q (dealate), Itoman, Okinawa-jima, 18.viii.1991, Y. Yamanouchi leg. (Figs 2b , 4b , 5b ).

Distribution

in Japan. Kyushu and throughout the Nansei Islands ( Terayama et al. 2014).

Remarks.

Tetramorium cf. kraepelini belongs to the T. scabrosum group (sensu Bolton 1977). The so-called T. kraepelini can be a complex of sibling species. As only one queen was available for examination the variation in structure and sculpture is unknown. One queen from a colony collected from Central Thailand and tentatively identified as T. kraepelini is very similar to the queen examined above; however, the distance between the posterior ocelli is slightly longer than in the Japanese form.

Figures

Figure 1. Some important characters used in the key to species a-e petiole in profile view a T. pacificum b T. lanuginosum c T. bicarinatum d T. smithi e T. tsushimae f-h anterior half of first gastral tergite f T. bicarinatum g T. simillimum h T. lanuginosum i-k antennal scape showing pilosity on its anterior margin l-n left hindtibia i, l T. cf. kraepelini j, m T. nipponense k, n T. simillimum o, p configuration of ocelli o T. tanakai p T. cf. kraepelini.

Figure 2. Japanese Tetramorium queens: habitus in profile view a T. bicarinatum (Nagashima, Kagoshima-ken, Kyushu) b T. cf. kraepelini (Itoman, Okinawa-jima, Okinawa-ken) c T. lanuginosum (Komi, Iriomote-jima, Okinawa-ken) d T. nipponense (Umi-jinja, Shikano-shima, Fukuoka-shi) e T. pacificum (Upper Thompson Nature Park, Singapore) f T. simillimum (Yoron-jima, Amami Is., Kagoshima-ken). (Same specimens were used for ' head in full-face view' and ' habitus in dorsal view').

Figure 4. Japanese Tetramorium queens: head in full-face view a T. bicarinatum b T. cf. kraepelini c T. lanuginosum d T. nipponense e T. pacificum f T. simillimum g T. smithi h T. tanakai i T. tsushimae.

Figure 5. Japanese Tetramorium queens: habitus in dorsal view a T. bicarinatum b T. cf. kraepelini c T. lanuginosum d T. nipponense e T. pacificum f T. simillimum.