Temnothorax haveni

Temnothorax haveni has been collected from semi-open to closed canopy secondary forests throughout the territory of Hong Kong, China. Specimens are mostly found within leaf litter samples but have also been attracted to ground baiting. One worker of T. haveni was collected twenty metres above the ground in a tree from an arboreal bait sample within a secondary forest. An additional specimen was hand collected along a waist high handrail and another from a flight interception trap (vane trap) hung from a tree at head height. These samples may indicate T. haveni forages on shrubs or understorey vegetation, as well as within trees and could therefore be a predominately arboreal species, which may also forage occasionally on the forest floor. However, it is difficult to rule out individuals falling from plants due to unintentional vegetation interaction by samplers, which may explain specimens from Winkler samples and ground hand collection. Moreover, the lack of any whole nest samples from the mostly ground based sampling effort in Hong Kong (e.g., Winklers), indicates this species may not nest in leaf litter, with only singletons found and no reproductive caste thus far collected.

While infrequently collected within Hong Kong, perhaps due to limited sampling towards arboreal species at this point, the species appears relatively widespread, being found on most larger islands and continental parts of the SAR (Fig. 5). Temnothorax haveni is thus expected to be found in the nearby province of Guangdong which shares a similar climate and habitats as Hong Kong.

Identification
Head subquadrate; lateral margins of head subparallel in full face view; clypeus with longitudinal carinae extending only in the anterior half; scapes not reaching occipital head margin; in lateral view promesonotum convex, followed by a concave mesopropodeal depression at the junction with the propodeum; promesonotal suture visible in lateral view only; metanotal groove absent; propodeal spines well-developed with thick base, long and curved pointing backwards; head and mesosoma glabrate; head, mesosoma and gaster covered with scarce erect, stout setae. Core body concolorous ochreous-yellow.

Temnothorax haveni would key out to Temnothorax zhejiangensis in Zhou et al. (2010) and shares several morphological characters. These characters include:
 * the presence of erect setae on the mesosomal dorsum
 * a pair of long slightly downcurved propodeal spines
 * humeri rounded in dorsal view
 * a short petiole peduncle
 * petiole that is longer than high in lateral view.

However, various characters differ, including:
 * the sculpture on the head dorsum
 * lateral and dorsum mesosoma being predominately glabrate in T. haveni rather than punctate in T. zhejiangensis.
 * the mesosomal outline differs greatly between both species with a convex promesonotum followed by a distinct concavity forming a weak promesonotal dome in T. haveni but only slightly convex across its whole length in T. zhejiangensis
 * the petiole peduncle is narrower and slightly longer in T. haveni than in T. zhejiangensis being broader and shorter
 * the petiole node in T. haveni has an acute dorsal apex within T. zhejiangensis is subtriangular with a narrowly rounded dorsum

Similarly, T. haveni might be mistaken for Temnothorax ruginosus but these species can be differentiated by size (T. haveni WL 0.61–0.69; T. ruginosus WL (ML in Zhou et al. (2010)) 1.80–1.84), as well as head and mesosomal sculpturing and the mesosomal outline. Temnothorax haveni may also be mistaken for Temnothorax barrettoi, however, both species can be differentiated by the glabrate sculpture and more scarce erect stout setae over the body of T. haveni.

We believe the above characters distinctly differentiate T. haveni from its congeneric species due to their uniqueness and consistency across all specimens examined. In fact, the lack of sculpture, particularly on the head, combined with distinct mesopropodeal depression, makes T. haveni morphologically distinct amongst Chinese Temnothorax. Further description of species of Temnothorax from other regions of Southeast Asia were examined with no species satisfying all characters.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 * RedText|haveni}}. Temnothorax haveni Lee, Hamer & Guénard, in Hamer et al., 2023: 124, figs. 3-5 (w.) CHINA (Hong Kong).

Type Material
Holotype CHINA • worker; Hong Kong SAR, Hong Kong Island, Aberdeen Reservoir; 22°15′32.04″ N, 114°9′34.56″ E; 190 m a.s.l.; 27 Jun. 2017; Roger H. Lee and Yuet Yin Ling leg.; ground baiting; ZRC RHL03433.
 * Paratypes (n = 8) CHINA – Hong Kong SAR • 1 worker; Mui Wo (Lantau Trail); 22°15′41.76″ N, 114°0′6.84″ E; 38 m a.s.l.; 15 Aug. 2022; André Ibáñez and Matthew T. Hamer leg.; Winkler; HKBM ANTWEB1010974 [MW1T1W4-5] • 1 worker; Hong Kong Island, Lung Fu Shan; 22°16′45.48″ N, 114°8′13.92″ E; 231 m a.s.l.; 14 Apr. 2022; Matthew T. Hamer leg.; hand collection on ground; HKBM ANTWEB1010976 • 1 worker; Hong Kong Island, Aberdeen Reservoir; 22°15′32.04″ N, 114°9′34.20″ E; 192 m a.s.l.; 27 Jun. 2017; Roger H. Lee leg.; ground baiting; HKBM RHL03467 [RHL5265] • 1 worker; Hong Kong Island, The Peak; 22°16′24.96″ N, 114°8′20.04″ E; 391 m a.s.l.; 11 Jul. 2017; Roger H. Lee leg.; hand collection; HKBM RHL03474 [RHL5272] • 1 worker; Tai Po Kau Nature Reserve; 22°25′12.72″ N, 114°10′35.76″ E; 349 m a.s.l.; 23 Aug. 2022; Shaolin Han leg.; arboreal baiting, 20 meters high; IBBL ANTWEB1010993 [TPK_S1_T3] • 1 worker; Fanling, Fanling Golf Course; 22°29′25.44″ N, 114°6′37.08″ E; 48 m a.s.l.; 23 May 2022; Matthew T. Hamer and André Ibáñez leg.; ground baiting; IBBL ANTWEB1010975 [FGE1T2B2-1] • 1 worker; Girl Guides Pok Hong Campsite; 22°22′16.68″ N, 114°11′46.68″ E; 84 m a.s.l.; 24 Jun.–1 Jul. 2022; Matthew T. Hamer and André Ibáñez leg.; flight interception vane trap; IBBL ANTWEB1010987 [GGPH2V2-1] • 1 worker; Tsing Yi, Tsing Yi Peak; 22°20′35.16″ N, 114°5′59.64″ E; 244 m a.s.l.; 16 Mar. 2018; R. Cheung and M. Law leg.; Winkler; IBBL ANTWEB1016704 [TYP S1-R].