Presbistus vitivorus, Bresseel & Constant, 2022

Bresseel, Joachim & Constant, Jerome, 2022, Extension of the phasmid genus Presbistus to Cambodia with a new species and notes on genitalia and captive breeding (Phasmida, Aschiphasmatidae, Aschiphasmatinae), Journal of Orthoptera Research 31 (2), pp. 105-117 : 105

publication ID	https://dx.doi.org/10.3897/jor.31.78520
publication LSID	lsid:zoobank.org:pub:94C8E222-0843-41CB-8629-3DACD4228BF1
persistent identifier	https://treatment.plazi.org/id/5E8A823B-4C12-4A5F-8FE8-4DAE19D8FB2B
taxon LSID	lsid:zoobank.org:act:5E8A823B-4C12-4A5F-8FE8-4DAE19D8FB2B
treatment provided by	Journal of Orthoptera Research by Pensoft
scientific name	Presbistus vitivorus
status	sp. nov.

Treatment

Presbistus vitivorus sp. nov.

Figs 1 View Fig. 1 , 2 View Fig. 2 , 3 View Fig. 3 , 4 View Fig. 4 , 5 View Fig. 5 , 6 View Fig. 6 , 7 View Fig. 7 , 8 View Fig. 8 , 9 View Fig. 9 , 10 View Fig. 10 , 11 View Fig. 11 , 12 View Fig. 12

Diagnosis and differentiation. -

The new species is morphologically most similar and believed to be closely related to two Bornean species: Presbistus marshallae Bragg, 2008 and P. appendiculatus Bragg, 2001. All three species have a cleft anal segment in males, with the left anal lobe (lal) shorter than the right (ral), and the right anal lobe twisted. In P. vitivorus sp. nov., ral first curves down towards the front and later upwards, projecting between the right cercus and the posterior margin of tergum IX. Sternite VII of females of the new species is not rounded or bilobed and does not notably project over the base of the operculum. Instead, the posterior portion of tergum VII is slightly narrowing with the praeopercular organ present as a posterior depression with indistinct lateral carinae and concave posteriorly. The new species also has relatively shorter hind wings compared to most of the other species of the genus. There is only a single species with two subspecies that have shorter hind wings: Presbistus asymmetricus viridialatus Seow-Choen, 2020 and Presbistus asymmetricus asymmetricus Giglio-Tos, 1910.

Etymology. -

The species name is formed from the plant genus name Vitis , belonging to the family of the grapevine Vitaceae and the suffix forming adjective - vorus (feminine - vora, neuter - vorum) meaning “eating” or “devouring”. It refers to the feeding preference of the species for plants of the family Vitaceae.

Type material. -

Holotype: CAMBODIA • ♂; Pursat prov., Phnom Samkos; 12°13'02"N, 102°55'07"E; 15-18 October 2016; GTI project; Leg J. Constant & J. Bresseel; I.G.: 33.345; RBINS. Paratypes: CAMBODIA • 7♂, 22♀; same collection data as holotype; 4♂, 19♀: RBINS; 2♂, 2♀: RUPP; 1♂, 1♀: VNMN.

Additional material. -

CAMBODIA • 10♀; Preah Vihear prov., Be Treed Adventures ; 16-21 October 2017, 13°29'44"N, 104°42'36"E; GTI Project; Leg. J. Constant & X. Vermeersch; I.G.: 33.551 GoogleMaps ; 8♀: RBINS; 2♀: RUPP • 3♀; Preah Vihear prov., Be Treed adventures; 16-21 October 2017, 13°29'44"N, 104°42'36"E; GTI Project; Leg. J. Constant & X. Vermeersch; I.G.: 33.551; Ex breeding Tim Bollens, 2018; RBINS GoogleMaps • 21♀; Preah Vihear prov., Be Treed adventures; 16-21 October 2017; 13°29'44"N, 104°42'36"E; GTI Project; Leg. J. Constant & X. Vermeersch; I.G.: 33.551; Ex breeding Tim Bollens, 2019; RBINS • Six eggs; same data as holotype; RBINS; RUPP GoogleMaps .

Remark. -

Living females from Phnom Samkos have the alae slightly projecting over the posterior margin of tergum V, but not reaching half of tergum VI. In living females from Be Treed, the alae are longer and slightly but noticeably projected over half of tergum VI. Breeding efforts have proven that wing length is a stable feature throughout successive generations. Therefore, even if no other differences could be observed, the specimens from Be Treed are not listed as type material.

Description. -

Male. (Figs 1 View Fig. 1 - 5 View Fig. 5 ) Body. Setae scattered over complete body, more concentrated in certain areas. Head, pro- and mesonotum brown with distinct black patches. Wings with blackish tegmina; costal area of alae brown with black markings and with basal portion of radius green, anal area infuscate. Femora brownish dorsally with black apex. Tibiae brownish, protibiae with black base and apex; mesotibiae with black apex and metatibiae with indistinct black marking apically.

Head. (Fig. 1C, E View Fig. 1 ) Flattened dorsally, wider than long with a shallow longitudinal impression posteriorly. Eyes strongly protruding. Two minute impressions between the bases of antennae. Antennae reaching about half of abdomen; scapus subcylindrical, roughly as long as pedicellus. Pedicellus cylindrical. First flagellomere longer than pedicellus; flagellomere II shorter than half the length of previous one; following segments varying in length.

Thorax. (Fig. 1C, E View Fig. 1 ) Pronotum longer than wide with posterior margin concave and with a median line in the prozona; prozona slightly higher than metazona from lateral view; lateral margins slightly concave from dorsal view, posterior margin more or less straight. Mesonotum about one third longer than pronotum and parallel-sided; anterior margin slightly concave with raised rim.

Wings. (Fig. 1A, B View Fig. 1 ) Tegmina small, elongate, triangular, and apically acute; pointing straight upwards. Hind wings reaching roughly halfway tergum VI.

Legs. (Fig. 1A, B View Fig. 1 ) Profemora incurved basally. Femora with carinae indistinct, outer ventral carinae with few minute spines. Tibiae with carinae indistinct.

Abdomen and terminalia. (Figs 1A, B, D View Fig. 1 , 2 View Fig. 2 - 5 View Fig. 5 ) Terga II-VII of uniform width and terga II-VI only slightly varying in length; tergum VII (t7) distinctly shorter; tergum VIII (t8) and IX (t9) widening towards the posterior; X narrower than IX. Anal segment (as) with indistinct mediolongitudinal carina, slightly widening towards the posterior; apex notched. Right anal lobe (ral) broad at base, distinctly elongated and strongly twisted and curved, projecting between cercus and posterior margin of tergum IX. Left anal lobe (lal) distinctly shorter than right one and curved. Cerci (ce) black and long, incurved and round in cross section with an apical tooth. Poculum bulgy and angular (110° angle), posterior part with fine mediolongitudinal carina, apex rounded.

Vomer (Fig. 4 View Fig. 4 ) well developed. Body (b) with narrow base, distinctly elongated, tapering and ending in an apical spine (as); ventral part of body distinctly longer than dorsal part. Left and right basal apodemes (lba, rba) narrow and elongated, almost as long as the vomer body. External body separated from internal apodemes by sclerotized connective ring (cr). Apodemes almost parallel, slightly directed towards each other.

Aedeagus (Fig. 5 View Fig. 5 ) with spatulate, elongate, and curved basal apodeme (ba) prolongated anterodorsally by a strongly sclerotized plate (dorsal sclerite). Sclerotized plate with elongated club-shaped right basal process (rbp), with blunt subtriangular left basal process (lbp) and with elongated curved dorsal process (dp) bearing minute teeth on anterior surface (Fig. 5F View Fig. 5 ). Caudal portion of aedeagus composed of a series of membranous lobes (ml).

Female. (Figs 6 View Fig. 6 , 7 View Fig. 7 )

Body. Setae scattered over complete body, more concentrated in certain areas. Female colored as male except for abdomen. In the female, tergum VII conspicuously paler than the rest of the abdomen.

Head. (Fig. 6C, E View Fig. 6 ) About as long as wide, flattened dorsally. Eyes strongly protruding. Two minute impressions between the bases of the antennae. Antennae reaching about half of abdomen; scapus flattened at base, cylindrical at apex, slightly longer than pedicellus. Pedicellus cylindrical. First flagellomere longer than pedicellus; flagellomere II shorter than half the length of previous segment; following segments vary in length.

Thorax. (Fig. 6C, E View Fig. 6 ) Pronotum longer than wide with anterior margin slightly concave and with a median line in the prozona; prozona slightly higher than metazona from lateral view; impression between pro- and metazona centrally flattened, almost circular, sublaterally with a minute hole; lateral margins slightly concave from dorsal view, posterior margin more or less straight. Mesonotum almost twice as long as pronotum and parallel-sided, with posterior margin slightly concave with a raised rim and anterior margin almost straight.

Wings. (Fig. 6A, B View Fig. 6 ) Tegmina small, elongate, triangular, and apically acute; pointing straight upwards. Hind wings projecting over posterior margin of tergum V but not reaching posterior margin of tergum VI.

Legs. (Fig. 6A, B View Fig. 6 ) As in male.

Abdomen. (Figs 6A, B, D View Fig. 6 , 7 View Fig. 7 ) Terga II-V of uniform width, terga VI-VIII slightly widening towards the posterior (this feature usually only visible in living specimens and especially in females with the abdomen swollen with eggs). Terga VII-X getting progressively shorter with VIII-X tectiform. Tergum VIII expanding laterally with lateral margin rounded. Anal segment slightly shorter than tergum IX; apex concave with minute epiproct visible in dorsal view. Cerci narrow, circular in cross section. Sternum VII with praeopercular organ present as a posterior depression with indistinct lateral carinae, indistinctly projecting over base of subgenital plate and concave posteriorly. Subgenital plate with anterior portion globose and with minute impression basally; posterior portion with distinct mediolongitudinal carina, narrowing towards the posterior with apex roundly pointed.

Nymph. (Fig. 8 View Fig. 8 ) Newly hatched nymphs have a pinkish body and head. Antennae longer than head and body combined, orange with evenly spaced black markings. Legs slightly setose and completely orange.

Egg. (Fig. 9 View Fig. 9 ) Measurements [mm]: length 1.9, width 0.9, height 1.5. Capsule dark reddish brown, surface minutely punctuate without setae; lentil shaped and laterally compressed. Micropylar plate colored like capsule, long and narrow, longitudinally carinate laterally and medially, extending from the operculum across the polar end and back to the operculum. Micropylar cup distinct, displaced towards the polar area; operculum elongate oval, not punctuate, with a raised elongate oval ridge centrally.

Biology. -

Wild specimens were found in Phnom Samkos on Vitaceae (identification of the wild Vitaceae by A. Trias-Blasi, pers. com., VII.2019) species belonging to the genus Tetrastigma (Miq.) Planch. or Cayratia (Baker) Suess. and were fairly numerous on their host plants (Figs 10 View Fig. 10 , 11A-D View Fig. 11 ). Males and females were present in this population, with most males found in copula (Fig. 10E View Fig. 10 ). In Be Treed, they were common on Vitaceae of the genus Ampelocissus Planch., but only females were found, thus this particular population seems to be parthenogenetic (Fig. 11E-G View Fig. 11 ). From this latter parthenogenetic population, P. vitivorus sp. nov. was cultured by T. Bollens (Belgium) on various Vitaceae ( Parthenocissus spp., Cissus alata Jacq., Vitis vinifera L.) of which the latter species was the preferred alternative food. The eggs are dropped to the ground, and the young nymphs are bright red in color after hatching but turn green after a few days. They hide mainly underneath leaves and are very fast and hectic when disturbed. Incubation of eggs was performed without a diapause and lasted 6 months, or with a 5-6 months diapause in the refrigerator and then lasted 4 months after the diapause. Females produce many eggs, with up to 10 eggs dropped per day by each female.