Hemitrochostoma altilabris Bergroth, 1913

Redei, David & Jindra, Zdenek, 2015, A revision of the genus Hemitrochostoma (Hemiptera, Heteroptera, Plataspidae), ZooKeys 495, pp. 63-77 : 69-70

Taxon classification Animalia Hemiptera Plataspidae

Hemitrochostoma altilabris Bergroth, 1913 Figs 5-6, 9-11, 12-13, 16-21, 24-27, 28-31

Hemitrochostoma altilabris Bergroth, 1913: 177. Syntype(s) (male): [Malaysia:] Borneo, Sarawak, Trusan; depository unknown (see Discussion).

Inflatilabrum lambirense Tomokuni, 2012: 40. Holotype (male): Malaysia: Borneo, Sarawak, Lambir Hills National Park, Inoue Trail; NSMT. New subjective synonym.

References.

Rédei and Bu 2013: 272 (morphology).

Material examined.

MALAYSIA. Borneo: Sarawak, Kapit Distr., env. of Rumah Ugap, valley of Sut River, 3-9.iii.1994, leg. P. Bílek (3 males 3 females ZJCP, 1 male 1 female HNHM).

Diagnosis.

Differs from the only known congener, Hemitrochostoma rutabulum sp. n., by the less-dilated mandibular plates in both sexes and the less-produced anterior angles of the pronotum (not extending to anterior margin of eye in dorsal view) (Figs 5-6).

Redescription.

Male and female. Photographs of the habitus and diagnostic characters of both sexes were presented by Tomokuni (2012) under the name Inflatilabrum lambirense .

Colour and integument. Dorsum of body brown, following parts ochraceous: mandibular plates except their narrow lateral margin, a middorsal vitta between base of clypeus and base of head usually narrowing towards base of head; explanate lateral margin, a pair of transverse submedian fasciae between collar and calli, some suffused spots at posterior margin of calli, and humeral tubercles on pronotum; a pair of distinct or indistinct spots at basal tumescence and occasionally an indistinct median vitta on disk of scutellum; visible portion of costal margin of fore wing; lateral and posterior margins of scutellum broadly marmorated with ochraceous of various extent; legs ochraceous, antennae slightly darker, brownish ochraceous; venter of head brown, ventrally visible surfaces of mandibular plates and clypeus ochraceous, labium ochraceous, ventrally visible portions of thorax and abdomen brown, explanate lateral margin of propleuron ochraceous, abdominal ventrites somewhat lighter brown than pterothoracic pleura, lateral margin and an adjoining sublateral spot at anterior margin of each of ventrites III–VII ochraceous. Integument and vestiture as in the generic description.

Structure. Head (Figs 5-6) with lateral margin of mandibular plates weakly (male) or insignificantly (female) emarginate anteriad of eye, then more or less straight, slightly diverging anteriad (male) or subparallel (female), apically abruptly truncate (male, female). Pronotum (Figs 5-6) with anterolateral angles distinctly produced anteriad but not reaching anterior margin of eye (male, female). Other characteristic of the exoskeleton as in generic description. A detailed description, habitus photos and photos of diagnostic characters of both sexes were provided by Tomokuni (2012) under the name Inflatilabrum lambirense .

External male genitalia. Genital capsule (Figs 12-13) with a pair of weak lateral notches in posterior view, therefore lateral margins appearing weakly emarginate in most exposed view; cuplike sclerite (Fig. 12-13: cus) large, occupying most of ventral inner surface of genital capsule, visible as a transverse rim-like plate along ventral margin of posterior aperture of genital capsule in posterior view. Paramere as in Figs 16-17. Phallus (Figs 18-21, 24-25): support bridge complex (Fig. 21: sbc) and basal plates (Fig. 21: bp) strongly fused, without window-like interspace between them, each with a pair of robust, laterally directed arms dorsally; erection fluid pump (Fig. 21: erp) short; support bridge prolongation (Figs 18-19: sbp) forming a pair of rather thin bands running parallel with ductus seminis (Figs 18, 20: ds); phallotheca (Fig. 18: phth) dorsally and laterally sclerotized, ventrally membranous, sclerotized lateral wall produced into a pair of rounded lobes ventrodistally (cf. Figs 18, 20); conjunctiva voluminous, greatly membranous, provided with a pair of dorsolateral membranous, partially sclerotized processes (probably homologous with cp-I of Tsai et al. 2011) (Figs 18-20: cp-I) and a pair of lateral processes which are broadly membranous proximally but terminating in 2 strongly sclerotized, long, spine-like projections distally (Figs 18-20: cp-II1 and cp-II2); endophallic reservoir (Figs 18-19: res) small, with a pair of ventral protuberances associated with distal parts of support bridge prolongation, separated by basal portion of aedeagus s. str. by a deep, narrow incision; aedeagus s. str. (Figs 18, 20, 25: aed) greatly elongate, narrow, tubular, strongly curved in an S-shape in the sagittal plane, narrowly enclosing the tubular endophallic duct (Fig. 24: end) in most of its length except in the area of a strongly elevated, carina-like dorsal lump immediately distad of its middle which encloses an inner chamber (Fig. 24: ich); apex of aedeagus s. str. obliquely truncate.

External female genitalia. Posterolateral margins of valvifers VIII (Fig. 28: vf8) (adjacent with ventrite VII) nearly straight; laterotergites IX (Fig. 28: lt9) subhorizontal, relatively narrow; gynatrium (Fig. 30: gy) short, transverse, contralateral ring sclerites (Fig. 30: rs) fused into a single uninterrupted ring; spermatheca (Fig. 29: sth, Fig. 31): proximal portion of spermathecal duct broad, thick-walled, with a broad lumen, gradually narrowed in its middle portion, distally narrow, tubular; intermediate part of spermatheca short and thick, flexible zone occupying about its proximal half; proximal and distal flanges relatively small; distinct septum and fretum present; apical receptacle simple, globose.

Measurements (in mm) (N = 3 males / 3 females). Body length 6.2-6.5 / 6.0-6.4; median length of head to apex of clypeus 1.48-1.54 / 1.42-1.50, to apex of mandibular plates 1.68-1.80 / 1.70-1.75, greatest width across mandibular plates subapically 1.52-1.58 / 1.38-1.42, width across eyes 1.76-1.78 / 1.78-1.81, interocular distance 1.34-1.36 / 1.33-1.39, interocellar distance 0.66-0.67 / 0.64-0.71, oculo-ocellar distance 0.27-0.30 / 0.30-0.33; lengths of antennal segments I: IIa: IIb: III: IV as 0.59-0.68 / 0.58-0.64: 0.10-0.12 / 0.09-0.10: 0.96-1.01 / 0.93-0.96: 0.80-0.84 / 0.82-0.86: 0.92-0.95 / 0.86-0.96; median length of pronotum 1.62-1.66 / 1.60-1.72, humeral width 3.41-3.50 / 3.56-3.68; median length of scutellum 3.08-3.10 / 3.16-3.45, greatest width 3.58-3.66 / 3.92-4.00.

Immatures.

Description and photograph of the 5th-instar larva were presented by Tomokuni (2012) under the name Inflatilabrum lambirense .

Distribution.

The species is known only from a few localities, all in Sarawak, Borneo, Malaysia. - MALAYSIA. Borneo: Sarawak: env. of Rumah Ugap!, Trusan ( Bergroth 1913), Lambir Hills National Park (Tomokuni 2002) (Fig. 33).

Bionomics.

The bionomics of Hemitrochostoma altilabrum (as Inflatilabrum lambirense ) was discussed by Tomokuni (2012). The species feeds on sap of the trunks of Dryobalanops aromatica C.F.Gaertn. ( Dipterocarpaceae ) and another, unidentified tree species. Adults and larvae live in shelters under dead peeling bark of the lower regions of the trunk created by mutualistic ants ( Formicidae : Camponotus spp.).

Discussion.

Hemitrochostoma altilabris was described based on an unspecified number of specimens (all males). The type depository was not indicated in the original description ( Bergroth 1913). The type(s) could not be located in the Zoological Museum of the University of Helsinki (L. Huldén, pers. comm.) currently housing most of the types of E. Bergroth ( Schuh and Slater 1995), and also was not found in other important depositories of Bergroth types: the Zoological Museum of the Humboldt University of Berlin (J. Deckert, pers. comm.), the Senckenberg Deutsches Entomologisches Institut in Müncheberg (S. Blank, pers. comm.), the HNHM, the Naturhistorisches Museum in Vienna, and the Natural History Museum in London (all of them visited by DR). Because the specimens examined by us were collected rather close to the type locality, and the males are in agreement with the description and illustrations of Bergroth (1913), they are readily identified as Hemitrochostoma inflatilabrum . Although the type material currently cannot be located, so far there is no doubt about the identity of this species and, therefore, designation of a neotype is not justified.

The detailed original description and illustrations of Inflatilabrum lambirense leave no doubt that this species is conspecific with Hemitrochostoma altilabris ; therefore, the following new subjective synonymies are proposed: Hemitrochostoma Bergroth, 1913 = Inflatilabrum Tomokuni, 2012, syn. n.; Hemitrochostoma altilabris Bergroth, 1913 = Inflatilabrum lambirense Tomokuni, 2012, syn. n.