Nagisavelia Watanabe, Nakajima et Hayashi 2023, gen. nov.
Creators: name: Watanabe, Kohei
name: Nakajima, Jun
name: Hayashi, Masakazu
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Mesoveliidae
Nagisavelia

description: Nagisavelia Watanabe, Nakajima et Hayashi, gen. nov.
[Japanese name: Nagisa-Mizukamemushi-zoku]
(Figs. 1–8, 11–24)
Type species. Nagisavelia hikarui sp. nov.
Description. Apterous form, small. Head very long; ocelli absent; eyes vestigial, with small ommatidia, located near base of head, with dense setae (Fig. 21); antennae long and slender, filamentous, shorter than body, without spines; ventral head very long, weakly carinate (Fig. 15); labium long, reaching posterior margin of abdominal sternum II; pronotum broad, posterior margin slightly arched; mesonotum broad, posterior margin slightly arched; metanotum broad, posterior margin straight; without wings; middle thoracic venter with single metasternal scent gland opening; legs slender and long, hind legs longest, spines absent, but hind tibia with weak spines; tarsi with three segments, first segment shortest, third segment longest (Fig. 22); lateral abdomen with longitudinal sulcus; male genital segment large, parameres symmetrical; female genital segment large, ovipositor ensiform, both sides moderated middle to apex (Fig. 17); gonoplacs large (Fig. 16); gynatrial sac small (Fig. 18).
Remarks. Nagisavelia gen. nov. can be distinguished from nine of the current mesoveliine genera by its relatively vestigial eyes (Table 1; Andersen & Polhemus 1980, 2003; Malipatil & Monteith 1983; Polhemus & Polhemus 1989). Cavaticovelia is similar to Nagisavelia gen. nov. in regard to its very long head, vestigial eyes, filiform antennae, and the long labium which reaches to the middle of the abdomen, but can be distinguished by the following combination of characteristics (Table 1): body royal-orange (body yellowish in Cavaticovelia); antennae shorter than body (antennae longer than body in Cavaticovelia); antennae without spines (with spines in Cavaticovelia); eyes with dense hairs (Fig. 21) (eyes with two short setae in Cavaticovelia: see Andersen & Polhemus 1980: fig. 47); ventral head weakly carinate (Fig. 15) (simple in Cavaticovelia); legs short (legs very long in Cavaticovelia: see Gagné & Howarth 1975: fig. 1); thoracic segment length I> II> III (Fig. 19) (I> III> II in Cavaticovelia); spines on legs absent but hind tibia weak (weak in Cavaticovelia); metatarsal segment length III> II> I (Fig. 22) (II> III> I in Cavaticovelia). In East Asia, Speovelia is similar to Nagisavelia gen. nov. but can be distinguished by the following combination of characteristics (Table 1): very long head, more than 1.8 times longer than width (less than 1.5 times as long as width in Speovelia); eyes vestigial (Fig. 21) (reduced in Speovelia: Fig. 25); eyes with dense setae (Fig. 21) (with two short setae in Speovelia); antennae shorter than body (longer than body in Speovelia); antennae without spines (with spines in Speovelia: Fig. 25); labium extends to middle of abdomen (to mesocoxae in Speovelia); ventral head weakly carinate (Fig. 15) (simple in Speovelia); spines on legs absent but hind tibia weak (strong in Speovelia); metatarsal segment length III> II> I (Fig. 22) (II> III> I in Speovelia: Fig. 28).
Etymology. The genus name is derived from the habitat “Nagisa” of the type species. In Japanese, “Nagisa” means the water edges of beaches.
description: Published as part of Watanabe, Kohei, Nakajima, Jun & Hayashi, Masakazu, 2023, Nagisavelia hikarui, a new genus and species of Mesoveliinae (Hemiptera: Heteroptera: Mesoveliidae) inhabiting shingle beaches in Japan, pp. 468-478 in Zootaxa 5353 (5) on page 469, DOI: 10.11646/zootaxa.5353.5.5, http://zenodo.org/record/10010393