Nylanderia picta (Wheeler, 1927)

Guénard, Benoit, 2023, A checklist of Nylanderia (Hymenoptera: Formicidae: Formicinae) from Hong Kong and Macao SARs, with an illustrated identification key for species in Southeast China and Taiwan, Zootaxa 5301 (5), pp. 501-539 : 525-527

Nylanderia picta

( Figure 20 ; Figure 26.B )

Diagnosis. Nylanderia picta can be distinguished from other species of Nylanderia from Southeast China by the combination of small eyes (MaI 91.4–104.7; REL 17.1–18.4) with six ommatidia in the longest row, short clypeus (ClL 0.11–0.132), and first segment of gaster without pubescence or with scarce pubescence.

Measurements (n= 3 workers). ClL 0.11–0.132; ClW 0.319 –0.327; HL 0.502 –0.514; HW 0.408 –0.426; EL 0.086 –0.092; MaD 0.083–0.09; IoD 0.292 –0.303; SL 0.558 –0.578; ML 0.607 –0.629; PrL 0.216 –0.234; PrW 0.291 – 0.302; PrFL 0.451 –0.463; MeL 0.128 –0.143; MeW 0.151 –0.154; PrpL 0.126 –0.132; PrpH 0.223 –0.245; PrpW 0.221 –0.225; PL 0.178–0.21; Ab3L 0.322 –0.325; TL 1.4–1.7; PMC 2–3; MMC 2–3; CI 80.2–84.9; DNI 51–51.9; IoI 69.5–73.6; OI 21.1–21.6; SI 135.5–138.3; REL 17.1–18.4; MaI 91.4–104.7.

Compare with: N. emmae , N. IBBL-01, N. yaeyamensis .

Morphology. Among all the species of Nylanderia recorded for Hong Kong, N. IBBL-04 is one of the species that most varies in terms of morphology. Eye and mesosoma length span a wide size interval, with variation in overall width (PrW, MeW, and PrpW). The ommatidia count remained the same in all specimens studied, which scale in size as the eyes get larger throughout the specimens’ series.

Body coloration was more or less stable throughout the studied series, with most specimens presenting a light yellow color throughout their bodies, with a few specimens being almost pale—the latter being, possibly, callow workers. Erect macrosetae color, which is consistently black or dark brown throughout the examined series, contrasts with the lighter body color.

Brassard et al. (2021) had already found this species in Macao, recognizing all specimens belonging to it as morphospecies and naming them as Nylanderia sp.3 BG and Nylanderia sp.6 BG.

Ecology. This species is quite widespread and can be found virtually in any habitat, at different elevations (122 m a.s.l. to 980 m a.s.l.), occurring in highly disturbed environments (e.g., Chek Lap Kok) and in preserved country parks and Nature Reserves (e.g., Ngong Ping and Tai Po Kau Nature Trail ).

Distribution. Although being abundant in Hong Kong and Macao, the distribution of N. IBBL-04 appears to be restricted to the Southeastern provinces of China and Vietnam. The species is also recorded for Shanghai ( Hua 2006), but it is not possible to determine if this record corresponds to a misidentification or if the species can occur as far north in China’s Central Coast.

Examined material. Hong Kong: (1 worker) Chek Lap Kok , 22.2953, 113.9354; 12.x.2015, Aw 8; (1 worker) same data as preceding, 22.2939 113.9331, 12.xii.2016, Aw 14; (1 worker) same data as preceding, 22.2929 113.9347, 29.xi.2016, Aw 12; (1 worker) same data as preceding, 22.2930 113.9339, 22.ix.2015, Aw 13; (1 worker) same data as preceding, 22.2943 113.9361, 30.ix.2015, Aw 10; (1 worker) same data as preceding, 22.2945 113.9357, 22.ix.2015, Aw 10; (2 workers) Gilwell Campsite , 22.360084 114.221857, elevation 438 m, 17.ix2021, Winkler, M. Hamer, GS 1T1W2; (3 workers) Sha Lo Wan , 22.2898 113.9069, 1.viii.2016, Lw 1; (1 worker) Hong Kong Island , Victoria Park, 21.vi.1999, S. Yamane col.; (1 worker) Southern , Pok Fu Lam, 22.26700 114.14380 ±500 m, elevation 248 m, 7.vii.2016, M. Pierce col., #Ba-IAS-08-01-05; (1 worker) same data as preceding, 22.26700 114.14380 ±500 m, elevation 248 m, 7.vii.2016, M. Pierce col., #Ba-IAS-08-01-08; (1 worker) Tai Po , Tai Po Kau, 22.39566 114.14997 ±500 m, elevation 245 m, 25.v.2016, Y. Luo col., #ISP0072; (1 worker) same data as preceding, 22.39566 114.14997 ±500 m, elevation 245 m, 25.v.2016, Y. Luo col., #ISP0078; (1 worker) same data as preceding, 22.43245 114.18593 ±500 m, elevation 77 m, 25.v.2016, Y. Luo col., #ISP0081; (1 worker) Lung Fu Shan , 22.2814 114.1373, elevation 122 m, 16.vi.2019, K.Chan col.; (1 worker) same data as preceding, 22.2785 114.1380, elevation 206 m, K. Chan col.; (1 worker) same data as preceding, 22.2794 114.1371, elevation 232 m, 17.vii.2019, K. Chan col.; (1 worker) same data as preceding, 22.2794 114.1349, elevation 240 m, 28.vi.2019, K. Chan col.; (1 worker) same data as preceding, 22.2814 114.1373, elevation 122 m, 16.vi.2019, K. Chan col.; (1 worker) same data as preceding, 22.2785 114.1380, elevation 206 m, 8.vi.2019, K. Chan col.; (1 worker) same data as preceding, 22.2785 114.1380, elevation 206 m, K. Chan col.; (1 worker) same data as preceding, 22.2794 114.1371, elevation 235 m, 17.vii.2019, K. Chan col.; (4 workers) Lung Fu Shan , 22.2784 114.1346, elevation 211 m, 23.viii.2019, K. Chan col.; (1 worker) Lung Fu Shan , 22.2782 114.1349, elevation 244 m, 11.ix.2019, S.Nooten & K Chan col.; (3 workers) Gilwell Campsite , 22.36010 114.22185, elevation 429 m, 17.ix.2021, M. Hamer col.; (1 worker) Tai Tam Reservoir , 22.24956 114.21320, elevation 57 m, 08.iv.2022, M. Hamer col.; (1 worker) Yee Ting Campsite , 22.40662 114.32657 28 m, 19.v.2022, M. Hamer col.; (9 workers) Tai Po Kau Headland , 22.43594 114.19250, elevation 59 m, 19.vii.2022, A. Ibañez & M. Hamer col.; (1 worker) Ngong Ping , 22.25252 113.90362, 446 m, 04.v.2022, M. Hamer & T. Silva col.; (1 worker) same data as preceding, 22.25349 113.90187, 478 m, 04.v.2022, M. Hamer & T. Silva col.; (1 worker) same data as preceding, 22.25349 113.90190, elevation 479 m, 04.v.2022, M. Hamer & T. Silva col.; (1 worker) same data as preceding, 22.25252 113.90362, 446 m, 04.v.2022, M. Hamer & T. Silva col.; (1 worker) same data as preceding, 22.25356 113.90192, elevation 473 m, 04.v.2022, M. Hamer & T. Silva col.; (5 workers) Tai Po Kau Headland , 22.43460 114.19270, elevation 76 m, 26.vii.2022, M. Hamer & T. Silva; (2 workers) Luk Keng , 22.52007 114.21490, 10 m, 03.viii.2022, A. Ibañez & M. Hamer col.; (2 workers) Tai Po Kau Nature Trail , 22.42751 114.18120, elevation 139 m, 18.viii.2022, A. Ibañez col.; (3 workers) Tai Po Kau Nature Trail , 22.42751 114.18120, elevation 139 m, 18.viii.2022, A. Ibañez col.; (1 worker) Ping Tong , 22.40642 114.30350, 116 m, 01.ix.2022, A. Ibañez col.; (5 workers) Tai Mo Shan , 22.42358102 114.128304, elevation 590 m, 14.ix.2022, M. Hamer & A. Ibañez col. ; Macao: (6 workers) Coastal Trail , 22º06.864’N 113º34.193’E, elevation 112 m, 17.v.2019, F. Brassard col.; (4 workers) Coloane Island , Morro de Hac Sa Family Trail , 22.1144N 113.56988E, elevation 53 m, 5.vi.2019, Ground Bait, F. Brassard col.; (2 workers) same data as preceding, 5.vi.2019 - 11.ix.2019, Ground Nest, F. Brassard col.

Figures

FIGURE 20. Nylanderia picta. A: Lateral view of the whole body; B: Dorsal view of the head; C: Dorsal view of the whole body.

FIGURE 26. Distribution maps for seven of the thirteen Nylanderia species recorded for Hong Kong.A: Nylanderia indica; B: Nylanderia picta; C: Nylanderia sharpii; D: Nylanderia taylori; E: Nylanderia yaeyamensis; F: Nylanderia yerburyi.