Timasius alveus Zettel et Pangantihon, 2020

Zettel, H. & Pangantihon, C. V., 2020, A NEW SPECIES OF THE TIMASIUS LIVENS SPECIES GROUP (HEMIPTERA: HETEROPTERA: HEBRIDAE) FROM CAMBODIA AND VIETNAM, Far Eastern Entomologist 405, pp. 8-14 : 10-13

Timasius alveus Zettel et Pangantihon , sp. n.

http://zoobank.org/NomenclaturalActs/ 0EC6EB6F-C6FA-485A-B1F1-A76BFBC4B36F

Figs 1–10

TYPE MATERIAL. Holotype – (macropterous male, Natural History Museum Vienna),

labelled “ Cambodia: Mondulkiri Prov. \ Saen Monourom City, W Kroeng \ Saen Monourom, N 12°26.58' \ E107°09.58', 612 m, 22.XI. \ leg. Pangantihon P592 (MO-4)” .

Paratypes: 1 macropterous male (in the collection of the first author, genitalia lost), same label data; 9 macropterous males, 3 macropterous females, labelled “ S Vietnam, 40 km NW

An Khe\ Buon Luoi, 14°10’N, 108°30’E\ 620-750m,28.3.- 12.4.1995 \ leg. Pacholatko &

Dembicky” (Natural History Museum Vienna, Zoological Collection of Biological Museum at Hanoi University of Science ) .

TYPE LOCALITY. Cambodia: Mondulkiri Province, Saen Monourom City, west of

Kroeng Saen Monourom Waterfall, N 12°26.58', E107°09.58', 612 m a.s.l.

HABITAT AT TYPE LOCALITY. The specimens were collected from wet rocks in the vicinity of the falls .

DESCRIPTION. Macropterous male. Measurements of holotype: BL 2.66, HL 0.61,

HW 0.49, A 2 L 0.25, PL 0.60, PW 1.18, MtL 1.02, AW 1.07. Indices: HI 125, AtI 82, EI 67,

AnI 57, PHI 241, PnI 197, MMI 43, MtI 87, AbI 223. Relative lengths of antennomeres 1 – 4

(in % of antennomere 2): 135: 100: 130: 223. Relative lengths of leg segments (in % of metatibia): profemur 55, protibia 60, protarsus 20, mesofemur 61, mesotibia 70, mesotarsus

22, metafemur 83, metatibia 100, metatarsus 27.

Measurements of paratypes (n = 10): BL 2.68–2.99, HL 0.62–0.66, HW 0.49–0.51, A 2 L

0.24–0.26, PL 0.61–0.65, PW 1.19–1.28, MtL 1.01–1.12, AW 1.06–1.27.

Colour ( Figs 1–2 ): Trunk black. Buccula yellow. Antenna black. Legs from coxa to base of femora yellow; distal parts of femora turning to brown. Tibiae and tarsi black. Each cell of forewing with relatively small frosted mark at base; membrane with indistinct greyish spots.

Pilosity: Dorsum of head, thorax, and corium with rather sparse, thin, golden, subcumbent pilosity, comparatively dense on anterior lobe of pronotum, mesoscutellum, and terminal vein of forewing. Venter and sides of body with thin, subcumbent, whitish pilosity.

Structures: Body stout, with rather short antennae and legs. Head ( Figs 3, 4 ) comparatively short; sides between anterior margin of eyes and small, rounded antennal tubercles slightly divergent. Preocular tubercles weakly developed. Middle furrow on posterior of head deep.

Anteclypeus shiny, compressed, in lateral aspect convex. Buccula ( Fig. 4 ) moderately wide,

with two round circular impression, posteriorly with two processes: dorsal one small and acute,

slightly pointing to side, ventral one hardly longer, apically acute, slightly curved medially.

lateral aspect; (5) mesoscutellum and metanotal elevation, dorsal aspect; (6) mesoscutellum and metanotal elevation, lateral aspect; (7) pygophore, dorsal aspect; (8) proctiger, dorsal aspect; (9) right paramere, lateral (external) aspect; (10) left paramere, lateral (external)

aspect.

Pronotum wide, sides with angular emargination; surface, except for anterolateral callosities and humeri, with deep punctures; anteriorly between paired swellings with three parallel, very deep longitudinal impressions. Metanotal elevation ( Figs 5, 6 ) short, 2.0 times as wide as long, subtriangular; apex sharply pointed in dorsal aspect, in lateral aspect free tip appearing truncated. Forewing posteriorly reaching end of abdomen, laterally distant from connexival margins. Ventral thoracic carinae as characteristic for the genus ( Fig. 2 ). Legs very slender,

not modified. Abdomen in dorsal aspect only slightly widened from base to midlength,

posteriorly ovate, almost evenly rounded apically, only weakly truncated. Abdominal venter strongly modified ( Fig. 2 ): sternum 3 with small, roundish tuft of erect setae at middle of hind margin; sternum 4 with broad pad of brown velvety pilosity; sterna 5–7 with broad, but shallow medial groove; groove margins laterally not crested, posteriorly sharply delimited by a raised transverse elevation of segment 8. Segment 8 short, constricted at midlength; anterior portion narrower than posterior portion which contains the genitalia; posterior part with a subterminal crest ventrally. Genitalia short and broad. Pygophore ( Fig. 7 ) symmetrical, strongly widened,

ventrolaterally extended into rounded lobes, (postero-) dorsolaterally extended into broad,

mesally curved and apically truncated lobes; distal part transverse, truncated. Proctiger ( Fig.

8) almost symmentrical, small, laterally with short ventrolaterally directed processes; apex rounded, bearing six short, very stout setae. Parameres ( Figs 9, 10 ) very small, slightly asymmetrical; left paramere with a larger dorsal tooth and with less developed setae than right paramere.

Macropterous female. Measurements of paratypes (n = 3): BL 2.72–2.82, HL 0.62–

0.64, HW 0.49–0.53, A 2 L 0.25–0.27, PL 0.60–0.66, PW 1.18–1.22, MtL 1.03–1.09, AW

1.08–1.15.

Colour, pilosity, and structures similar as in males. Abdominal sterna unmodified. Gono-

coxa flat, unmodified. Proctiger small, with some moderately long setae.

COMPARATIVE NOTES. Timasius alveus sp.n. clearly belongs to the T. livens species group as defined by Andersen (1981), Zettel & Chen (2000), and above. Timasius alveus sp. n.

shares a pointed ventral buccula tooth with T. minor from Pakistan and India, whereas all other species – described or undescribed, as far as known to the authors – possess truncated or broadly rounded ventral buccula teeth. The male of T. alveus sp.n. is unique in the group by both the sternal characteristics ( Fig. 2 ) and the broad genitalia ( Figs. 7, 8 ). The female can be differentiated from T. minor by larger size (BL 2.7 – 2.8 mm vs. 2.2 – 2.5 mm in T.

minor). Timasius alveus sp.n. is among the largest species of the T. livens group, together with

T. tachamoae Zettel, 2012 from Nepal (BL 2.6–2.8 mm) and T. livens (BL 2.6 mm) from

Thailand.

ETYMOLOGY. The species epithet is a noun in apposition; it is the Latin word for a shallow groove. The name refers to the large, round impression on the abdominal sterna of the male.

Figures

Figs. 1–2: Habitus of Timasius alveus sp. n., male, in dorsal (1) and ventral (2) aspect. © Harald Bruckner.

Figs. 3–10: Habitus of Timasius alveus sp. n., male: (3) head, frontal aspect; (4) head,