Rhagovelia freitagi Zettel, Laciny et Pangantihon, 2021

Zettel, H., Laciny, A. & Pangantihon, C. V., 2021, A new species of the Rhagovelia sarawakensis species group (Hemiptera: Veliidae) from Cambodia, Far Eastern Entomologist 422, pp. 1-9 : 3-7

Rhagovelia freitagi Zettel, Laciny et Pangantihon , sp. n.

http://zoobank.org/NomenclaturalActs/4bf0685c-498d-48a0-b93b-077e935dc7d4

Figs 1–8

TYPE MATERIAL. Holotype – apterous male labelled “ Cambodia: Mondulkiri

Prov. Saen Monourom City, Dakdam vill., Dakdam wf., N 12°24.65' E107°18.6',

811 m, 22.XI. leg. Pangantihon P591 (MO-3)” (Natural History Museum Vienna).

Paratypes: 2 apterous males, 5 apterous females collected with the holotype; 2

apterous males, 2 apterous females 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)” (Natural History Museum Vienna; Cambodian Entomology Initiatives at the Royal University of Phnom Penh; private collection of first author).

DIAGNOSIS. A species of the Rhagovelia sarawakensis group that is cha-

racterized by small size, short pronotum (apterous morph), moderately incrassate metafemur, unmodified sternites of the male, and horizontal tergite 8 of the female.

Habitus slender ( Figs 1, 2 ), size small (apterous male: 2.7–2.9 mm; apterous female: 2.8–3.1 mm). Long setae sparse. Trunk black, except pronotum anteriorly with orange mark. Coxae, trochanters, and bases of pro- and metafemora yellow

(mesocoxa brownish infuscated in some specimens). Jugum moderately broad and declivitous. Black spinulae present on proepisternum, meso- and metacoxa, lacking on procoxa. – Male: mesofemur without stout spines at base of flexor side. Hind leg

( Fig. 3 ): trochanter with a spiny tooth; femur with basal and distal row of teeth consisting of 8–10 and 8–11 teeth, respectively; tibia with strong dentition on flexor side, its teeth about as long as smaller teeth of distal row on femur. Proctiger slender ( Fig. 4 ). Paramere ( Fig. 5 ) with slender distal part; ventral outline beset with very long setae; apex narrowly rounded. – Female: Hindleg ( Fig. 6 ): femur with basal and distal row of teeth consisting of 2–5 and 7–9 teeth, respectively; tibia with a few small denticles. Abdomen ( Figs 7, 8 ) almost without modifications;

connexival margins of segments 2–4 slightly thickened; tergites 6 and 7 usually with a group of few moderately long setae at middle of hind margins; tergite 8

somewhat shiny; connexival corner only slightly acute, with some long, black setae.

DESCRIPTION. APTEROUS MALE. Measurements of holotype: Body length

2.94; maximum body width (at metapleura) 1.03. Head length 0.34, width 0.72; mini-

mum eye distance 0.15. Pronotum length 0.20, width 0.84. Mesonotum length 0.59.

Lengths of antennomeres, I 0.71, II 0.35, III 0.47, IV 0.46. Lengths of leg segments:

profemur 0.75, protibia 0.84, protarsus 0.02 + 0.03 + 0.18, mesofemur 1.38, meso-

tibia 1.06, mesotarsus 0.07 + 0.47 + 0.59, metafemur 1.16, metatibia 1.03, metatarsus

0.01 + 0.02 + 0.33. Metafemur width 0.26.

Measurements of paratypes (n = 3). Body length 2.72–2.75; maximum body width (at metapleura) 0.95–1.02. Head width 0.69–0.72. Pronotum length 0.20–0.22,

width 0.81. Mesonotum length 0.56–0.58. Metafemur width 0.24–0.26.

(paratype) (© A. Laciny).

Colour ( Fig. 1 ). Black. Pronotum anteromedially with transverse orange mark.

Juga and base of rostrum brown. Basal third to half of antennomere 1, all coxae and trochanters, basal half of profemur and basal fifth of metafemur pale yellow.

Pilosity. Head, sides of pronotum, and dorsoposterior margin of segment 8 with few long black setae. Antennomeres 1 and 2, and femora with the usual pattern of long black setae. Hind margins of tergites and laterotergites with transverse rows of moderately long subdecumbent gray setae. Short pilosity gray, dense and appressed.

Structures. Body slender, abdomen almost evenly converging towards apex. Head broader than anterior margin of pronotum. Juga smooth and shiny, without spinulae,

flat, about twice as long as broad, inclined towards antennal tubercles. Pronotum very short, along midline about 0.6 times as long as head (holotype). Mesonotum along midline 2.6–2.9 times as long as pronotum. Proepisterna bearing numerous small black spinulae.

Profemur on extensor side with hardly recognizable concavity, flexor side basally with black spinulae. Meso- and metacoxa dorsolaterally each with a group of small black spinulae. Hindleg ( Fig. 3 ) uniform; metatrochanter with long spine-like tooth,

in some specimens with one additional minute tooth; femora moderately thickened

(in holotype 4.5 times as long as wide), longest spine near midlength; basal row consisting of 8–10 short teeth, distally increasing in length; distal row consisting of

8–11 teeth distally decreasing in length; anterodistal row absent (a single minute tooth can be present). Metatibia stout, straight, with strong dentition at flexor side.

Laterotergites moderately sloping to almost horizontal. Tergite 5 about 2.2 times as broad as long. Tergite 7 about 1.6 times as long as tergite 6, and 1.2 times as long as broad. Abdominal sternites unmodified. Proctiger ( Fig. 4 ) slender, lateral wings hardly developed, base with paired fields of short, fine setae. Paramere ( Fig. 5 )

elongated, slender, especially the entire distal part; apex downcurved and narrowly rounded; basal part dorsally with 3 short setae; distal part ventrally with two rows of setae, setae of lateral row very long the distalmost one reaching apex.

paramere; 6 – hindleg of female; 7, – posterior part of abdomen of female, dorsal view; 8 –

the same, lateral view. (Pilosity omitted in Figs 3 and 6 , partly omitted in Figs 7 and 8 ).

APTEROUS FEMALE. Measurements of paratypes (n = 6): Body length 2.78 –

3.06; maximum body width (at metapleura) 1.00–1.09. Head width 0.72–0.73. Pronotum length 0.19–0.22, width 0.81–0.89. Mesonotum length 0.56–0.66. Metafemur width 0.22–0.23.

Colour ( Fig. 2 ). As in male.

Pilosity. Not much different from male. Connexival corner with small tuft of black setae. Tergites 6 and 7 (sometimes also 5) with a small group of medium-long setae at middle of hind margins.

Structures. Body slender, abdomen slightly broader than in male. Head broader than anterior margin of pronotum. Proportions of head length, pronotum length, and mesonotum length similar as in male; mesonotum along midline 2.6–3.2 times as long as pronotum.

Mesofemur without modifications. Metatrochanter without teeth (or rarely with

1 minute tooth). Metafemur ( Fig. 6 ) more slender than in male, with similar armature, but basal row with only 2–5 shorter teeth, distal row with 7–9 teeth. Metatibia with few minute denticles surpassing pilosity, straight.

In dorsal aspect ( Fig. 7 ) abdomen moderately slender; lateral margins of con-

nexiva slightly convex. Laterotergites moderately sloping; connexival margins 2–4

slightly thicker than 5–7. Tergites 1–7 slightly, transversely convex. Tergite 8 and proctiger pointing straight posteriad. Tergite 5 about 2.1 times as wide as long;

tergite 7 about 1.1 times as long as tergite 6 and about 1.2 times as wide as long;

tergite 8 slightly shorter than tergite 7. Connexival corner in lateral view weakly acute, almost rectangular. Gonocoxa plate-like. Proctiger small, knob-like.

MACROPTEROUS MORPHS unknown.

COMPARATIVE NOTES. Colour and metafemoral armature of R. freitagi sp. n.

resemble those of two species from Borneo, R. tebakang and R. samarinda

Polhemus et Polhemus, 1988, although the latter species has fewer teeth and its metatrochanter lacks a spiny tooth. However, these two species possess broad,

flattened juga (plates on each side of rostrum base), whereas the jugum of R.

freitagi sp. n. is narrower and sloping towards antennal tubercles. Further differences between R. freitagi sp. n. and R. tebakang are: procoxa without black spinulae in both sexes in R. freitagi sp. n. (versus black spinulae present in R.

tebakang); paramere of R. freitagi sp. n. with very slender distal part, moderately curved apex, and very long setae (versus distal part with broad base, strongly curved, pointed apex and rather short setae in R. tebakang ; compare Polhemus &

Polhemus, 1988: fig. 123); metatibia of female of R. freitagi sp. n. with fine, sparse dentition (versus strong, dense dentition in R. tebakang ); in connexival corner of

(apterous) female of R. freitagi sp. n. slightly acute, almost rectangular (versus terminating in a short acute angle in R. tebakang ). The more or less developed groups of setae at the hind margin of the female’s tergites 6 and 7 are not mentioned in the description of R. tebakang by Polhemus & Polhemus (1988).

ETYMOLOGY. This species is dedicated to Prof. Hendrik Freitag, limnologist at Ateneo de Manila University, the Philippines.

NOTES. The type locality ( Saen Monourom City , Dak Dam Village, Dak Dam

Waterfalls, 12°24.646’ N, 107°18.604’ E, h= 811 m) is a recreational area frequently visited by tourist for its waterfalls. It has patches of secondary growth forest and is surrounded by agricultural area ( Figs. 9, 10 ). The river is very muddy as a result of soil erosion from surrounding agricultural farming.

At present there are only three species of Rhagovelia recorded from Cambodia.

Rhagovelia inexpectata Zettel, 2000 (according to Zettel et al., 2017) and R. sumatrensis Lundblad, 1933 (unpublished data) differ strongly from the new species by a comparatively long pronotum of the apterous morphs (mesonotum length at most 2.5

times pronotum length), strongly infuscated mesocoxae, and – most of all – by some thick short setae at the mesofemoral base in males (Zettel, 2000). Four species of Rhagovelia are known from Laos and Vietnam. A key to the species of the R.

sarawakensis group from these three countries is presented below.

Key to the species of the Rhagovelia sarawakensis group recorded from

Figures

Figs 1, 2. Rhagovelia freitagi sp. n. 1 – habitus of male (paratype); 2 – the same, female

Figs 3–8. Rhagovelia freitagi sp. n. 3 – hindleg of male; 4 – proctiger of male; 5 –

Figs 9–10. Habitats of Rhagovelia freitagi sp. n. at the type locality (© C.V. Pangantihon).