Eurymetra santamariae, Zettel, 2020

Zettel, Herbert, 2020, New water strider species of Eurymetra from Madagascar (Hemiptera: Heteroptera: Gerridae), Acta Entomologica Musei Nationalis Pragae 60 (1), pp. 15-22 : 19-20

publication ID	https://doi.org/ 10.37520/aemnp.2020.002
publication LSID	lsid:zoobank.org:pub:A92539F8-4273-415B-A985-E0A0F03CE6A6
DOI	https://doi.org/10.5281/zenodo.3883346
persistent identifier	https://treatment.plazi.org/id/03F08790-FFB5-9D1E-B357-F96CFD5A7AF2
treatment provided by	Tatiana
scientific name	Eurymetra santamariae
status	sp. nov.

Treatment

Eurymetra santamariae sp. nov.

( Figs 6, 7 View Figs 6–7 , 11 View Figs 10–12 )

Type material (all in NHMW). HOLOTYPE: (apterous), NHMW #5292, “ Madagascar, Toamasina Province, Sainte Marie island (Nosy Boraha), Forêt de Kalalao, 18.XI.1993, leg. M. Madl”. ALLOTYPE: ♀, (apterous), NHMW #5291, same collection data, except “ 22.XI.1993 ”. PARATYPES: 5 ♀♀ (apterous), NHMW #5293–97, same collection data as holotype.

Description. Male. Measurements of holotype: BL 3.7; BW 2.77; HW 1.44; IO 0.47; PW 1.13; PHI 78; TiL 1.81; TaL 0.62; TTI 34. Antenna: A1–A4, 1.85, 0.89, 0.80, 0.58. Fore leg: Fe 1.82, Ti 1.81, Ta 0.12 + 0.50. Middle leg: Fe 5.35, Ti 3.35, Ta 1.24 + 0.18. Hind leg: Fe 5.83, Ti 2.55, Ta 0.23 + 0.27.

Structural characteristics. Eyes large, posteriorly surpassing sides of pronotum; their minimum distance on average smaller than in other species. Antennomere 1 with row of ca. 5–8 short oblique setae. Pronotum extremely small, in dorsal view of specimen, shorter than half of head length along midline. Apical process of protibia slender and slightly curved. Metanotum and tergites 1–3 medially fused. Shiny areas of dorsum hardly developed, reduced to pair of small areas at submedial yellow patches of mesonotum and a small zone posteriorly on metanotum. Paramere very narrow, moderately curved all over its length, distal part slender ( Fig. 11 View Figs 10–12 ).

Colour. Yellow marks comparatively small ( Fig. 6 View Figs 6–7 ). On head, anterior mark beween antennal tubercles small, orange, and interrupted in middle. Paired marks on pronotum narrow, medially hardly widened anteriorly, narrower than half-length of pronotum. Paired marks on metanotum widely distant from each other. Metapleuron above spiracle without yellow spot. On abdomen, small yellow marks on tergites 6–7, and on laterotergites 5–7. Body ventrally entirely yellow.

Female. Measurements of allotype: BL 3.7; BW 2.81; HW 1.38; IO 0.44; PW 1.10; PHI 78; TiL 1.58; TaL 0.58; TTI 37. Measurements of other paratypes (n = 5): BL 3.6–3.9; BW 2.75–2.95; HW 1.41–1.47; IO 0.45–0.48; PW 1.10–1.13; PHI 76–78; TiL 1.54–1.60; TaL 0.54–0.59; TTI 36–38.

Structural characteristics. Similar to male. Apical process of protibia slender and less curved. Shiny areas more developed, covering medial parts of tergites 1–3, interrupted by velvety patch; on metanotum posteriorly wide, medially triangularly extended to anterior margin.

Colour. As in male, yellow marks comparatively small ( Fig. 7 View Figs 6–7 ). On head, anterior mark between antennal tubercles small, in some specimens orange, in others interrupted in the middle. Paired marks on pronotum narrow, medially not or only slightly widened. On abdomen, small yellow marks on tergites 6–8, and on laterotergites 4–7 (those on laterotergites 4 and 7 indistinct in some specimens). Body ventrally yellow, mesosternum with large, triangular, blackish brown mark that is anteriorly prolonged until tip of rostrum (only studied in allotype).

Comparative notes. Eurymetra santamariae sp. nov. differs from both other species by the small pronotum (PHI = 76–80 vs. 85–90) and reduced shiny areas on the thoracic nota and tergites. Morphometrically it can also be distinguished by its smaller size from E. papaceki sp. nov., and by its longer protarsi from E. madagascariensis . Etymology. Named after the French name of the type area, Île Sainte Marie; noun in genitive case in apposition.