Leptogenys strena Zhou, 2001

Hamer, Matthew T., Lee, Jonathan Hon Chung, Tse, Cheung Yau Leo, Silva, Thiago S. R. & Guénard, Benoit, 2024, The Leptogenys Roger, 1861 (Formicidae, Ponerinae) of Hong Kong SAR with additional records from Guangdong, China, ZooKeys 1202, pp. 169-211 : 169-211

Leptogenys strena Zhou, 2001

Figs 4 A , 19 , 21 E new record

Leptogenys strena Zhou, 2001 a: 40 , 229, figs 39, 40 (w.) China (Guangxi).

Measurements.

Workers (n = 8): HL 1.39 – 1.47; HLL 1.16 – 1.23; HLA 0.23 – 0.31; HW 1.16 – 1.25; CML 0.21 – 0.26; SL 1.08 – 1.18; AII 0.2 – 0.25; AFI 0.18 – 0.22; AFII 0.15 – 0.19; EL 0.19 – 0.23; ML 0.72 – 0.8; PrL 0.85 – 0.95; PrH 0.59 – 0.64; PrW 0.82 – 0.99; WL 2.18 – 2.37; PeL 0.34 – 0.5; PeH 0.72 – 0.78; PeW 0.46 – 0.54; DPL 0.2 – 0.28; CI 82.86 – 87.03; CLI 15.38 – 17.74; SI 91.44 – 97.06; OI 16.6 – 18.83; LPI 144.33 – 216.28; DPI 166.19 – 249.29.

Morphological variation.

Upon examination of five specimens from the only collection locality in Hong Kong, it was noted that the number of teeth on the masticatory margin are not consistent but were always between three and five. Teeth were either conspicuous or barely discernible from the mandible margin, suggesting these teeth might be worn down and, or broken. A distinct diastema between the basal tooth and fourth tooth was, however, always present. The utility of teeth count as a differentiable and diagnosable character should likely be treated with caution unless combined with additional less variable characters.

Comparative notes.

Leptogenys strena is immediately recognisable within the Leptogenys of Hong Kong by the combined characters of small anteriorly positioned eyes, a subquadrate head, triangular mandibles with 3–5 teeth on the masticatory margin, and a distinctly red body colouration. Within the wider Leptogenys fauna of China, L. strena is most similar to L. lucidula Emery, 1895 and can be differentiated by the rounded posteroventral corner of the subpetiolar process, fewer teeth on the masticatory margin and the species overall larger size.

Distribution.

This species is so far only known from China, including Guangxi (type locality), Hunan, and Guangdong, and Hong Kong SAR ( Zhou et al. 2012; Xu and He 2015). Absence from other southern Chinese provinces is likely attributable to sampling effort.

Ecology.

Next to nothing is known about the ecology of L. strena . Specimens from Hong Kong are known only from Sunset Peak, Lantau Island. One collection was by J. R. Fellowes in 1992, and another in 2023 by A. Reshchikov using a ground SLAM trap, which was positioned in a tiny fragment of forest near the top of the mountain which yielded one further specimen. Further sampling efforts by members of Insect Biodiversity and Biogeography Laboratory have yet to collect additional specimens from this locality and from Hong Kong at large. The species’ small eyes might suggest leaf litter and / or nocturnal foraging.

Material examined.

Workers (n = 13): China • 8 workers; Hong Kong SAR, Lantau , Sunset Peak; 8 Oct. 1996; J. R. Fellowes leg.; HKBM MBS 015294 , MBS 006591 , MBS 006592 , ANTWEB 1010116 , ANTWEB 1010115 , ANTWEB 1010114 , ANTWEB 1010167 , ANTWEB 1010166 . • 4 workers; Guangdong Prov., Bai Yong ; 3 May. 1998; J. R. Fellowes leg.; HKBM ANTWEB 1010177 , ANTWEB 1010178 , MBS 006593 . • 1 worker; Hong Kong SAR, Sunset Peak ; 22.26104, 113.96683; 625 m a. s. l.; 06–25 May 2023; A. Reshchikov leg.; Secondary forest, SLAM ground; IBBL ANTWEB 1010228 .

Figures

Figure 4. Mandibular masticatory margin differences A Leptogenys strena (ANTWEB 1010114) B L. diminuta (GYOT 070).

Figure 19. Leptogenys strena (ANTWEB 1010114) A lateral view B dorsal view C head in full face view.

Figure 21. Further distribution maps of Leptogenys species recorded from Hong Kong A L. kraepelini B L. laeviterga C L. peuqueti D L. rufida E L. strena. The base map displayed shows tree canopy cover with the darker green areas indicating greater tree cover.