Oukhypencha, Magnien, 2023

Magnien, Philippe, 2023, New genera, species and subspecies of tessaratomine true bugs (Heteroptera: Tessaratomidae, Tessaratominae), Zootaxa 5375 (4), pp. 533-549 : 534-536

Oukhypencha gen. nov.

Type species. O. clemenceae sp. nov., by present designation.

Diagnosis. Medium sized Tessaratomina (19–26 mm), characterized by the following set of characters: head very small, with eyes and ocellae relatively large (ocular index 1.1–1.3, ocellar index 1.1–1.9), antennae long, little more than half (0.50–0.69) of habitus length; connexivum bicolourous; prosternal process lanceolate, rounded, sides not flattened, reaching or surpassing fore coxae.

Description. Body of the common pentatomoid shape ( Figs. 1–7 ), general hue bronze brownish above, of a lighter brownish ventrally; apex of fourth antennomere, apex of scutellum and forepart of each connexivum segment yellowish.

Head. Triangular, mandibular plates surpassing tylus, entirely punctate, save for a small area around ocellae; antennae 4-segmented, long; eyes and ocellae relatively large, ocular index 1.1–1.6.

Thorax. Pronotum sexangular, anterior, posterior and anterolateral margins nearly straight, posterolateral margins slightly bisinuous; callosities conspicuous, slightly marked. Scutellum triangular, longer than wide, its apex lanceolate. Metasternum with an elevated plate between coxae, bearing a rounded lanceolate process reaching or surpassing fore coxae, curved upwards at apex; evaporatoria small ( Fig. 23 ), in accordance with the description given for the tribe in Kment &Vilimova (2010).

Abdomen. Connexivum and urosternite margins straight; spiracles closer to margin than to middle of the sternites, trichobothria closer to middle, aft of transverse furrow.

Male genitalia (Figs. 11–13, 15–18). Pygophore of various shapes. Parameres having shape of a recurved blade, rounded at apophysis, sensorial lobe conspicuous, marked by a brush of setae about as long as parameral width; phallus bearing three or four processus, two of them strongly sclerotized, lateroventral process strong, scythe blade-shaped.

Female genitalia ( Figs. 19–22 ). Genital plates of general shape found in Tessaratomini . Spermatheca of common type in Tessaratomini ; apical receptacle (distal bulb) spherical with a basal “neck”, intermediate part (pump apparatus) with two well-developed flanges; spermathecal duct bipartite, anterior duct slender, posterior duct much wider, its anterior part slightly ovoid and longitudinally striated, rear part somewhat longer.

Etymology. The name Hypencha was crafted by its authors from the Greek ύπό, under and ἕγχος, sword. Ι added the prefix Ouk, from the Greek οὑκ, not, to imply it was not belonging in Hypencha .

Distribution. Peninsular Thailand, Malaysia, Indonesia (Java, Sumatra, Kalimantan).

Discussion. During this study, it became very apparent that previously identified material of H. ophthalmica was in fact a composite of at least four different species. The difficulties were a result of problems in the proper identification of the male of Stål’s species, and in the true generic placement of these taxa. Regarding the first problem, unfortunately, no specimens from Peninsular Thailand or Malaysia were available for study, so the decision was made to select the taxon with the most similar female genitalia as representing H. ophthalmica . It is one of the species from Sumatra, which is also among the closest to the type locality in Thailand.

Regarding the generic placement, it was quickly determined that for the involved taxa for which male specimens were available for study, none of them could fit in Hypencha . In fact, the variation in the male genitalia observed could have justified the creation of several different genera. Despite this variability, I have chosen to take a conservative approach and place all of these taxa in a single new genus, Oukhypencha gen. nov.

Its habitus is similar to that of other tessaratomine genera, the closest being Hypencha , the genus in which Stål originally placed H. ophthalmica . In general, the male genitalia are indeed very good characters to use in delineating tessaratomine genera. That is, the male genitalia are usually very similar among species within each genus, but they usually vary distinctly between genera (except for a couple, e.g., Embolosterna Stål and Tessaratoma Berthold 1), to the point that it is usually fairly easy to identify a genus from the examination of the male genitalia alone (see Kumar & Ghauri, 1970). The phallus of Hypencha , according to Kumar and Ghauri (1970), can be characterized by: “ Hypencha , Mucanum , Embolosterna and Tessaratoma , all have three pairs of conjunctival processes.” Hypencha is distinct in having two pairs of ventral conjunctival processes.

They add that the anteroventral one is membranous, and that the paramere is elongate, apically curved. Those descriptions do not match the organisation of the genitalia in the new genus.

The conjunctiva of Oukhypencha bears three or four pairs of processes, but even in those species with three pairs, their disposition is not homologous with those of Hypencha . Hypencha ( Fig. 15 ) lacks the ventral sclerotized and membranous processes, while Oukhypencha ( Figs. 16–18 ) species lack the proximoventral process. The dorsal process is sclerotized in Hypencha , while it is membranous in the new genus, except for O. florenceae which has two dorsal processes, the distal process is membranous, while the proximal process is sclerotized. Furthermore, the parameres ( Figs. 16–18 ) are not digitiform as those found in species of Hypencha ( Fig. 15 ), and they possess a conspicuous sensorial lobe with a dense brush of setae, which is absent in all examined specimens of Hypencha . Some differences, probably of less generic significance, listed in the diagnosis, can be found in the habitus. The antennae are relatively long for a tessaratomine, from about 50 to 70 % of the habitus length, whereas in Hypencha specimens, the antennae are about one-third of the habitus length, except for H. aeroplana in which it reaches less than half the habitus length. The ocellae are very large. The free part of the sternal process is rounded, not flattened, as is the case in Hypencha .

The connexivum is bicolorous in Oukhypencha , contrasting with unicolorous in Hypencha species. The apex of the scutellum is large and concolorous in Hypencha , while it is thin and more or less yellowish in Oukhypencha . The size of the eyes and ocellae is larger for Oukhypencha (ocular index 1.1–1.6, ocellar index 1.1–3.5) than for Hypencha (ocular index 1.3–1.6, ocellar index 2.0–5.5).

1 The synonymy between these two taxa should be examined on this basis; no character, except for the shape and colouration of the post-frenal part of the scutellum, has been found that can reliably separate the two genera. The conclusion of Kumar and Ghauri (1970) on this point is not sustainable, as their key would place E. vacca Martin, 1902 , within the genus Tessaratoma .

The choice to designate O. clemenceae n. sp. as the type species for this new genus was made on the basis that both male and female specimens where readily available in good numbers, which is not the case with the previously described O. ophthalmica for which male specimens are still unknown for the nominal subspecies.

Figures

FIGURES 1–3: habitus.—1–2 Oukhypencha clemenceae n.sp.; 1:—♂ (paratype, Sabah)—2: ♀ (West Kalimantan)—3: Oukhypencha florenceae n. sp. (holotype ♂). Scale 10 mm

FIGURES 4–6: habitus.—4 Oukhypencha ophthalmica ophthalmica Stål ♀ (holotype); 5–6: Oukhypencha ophthalmica sumaterensis n. sp.—5: ♂ (holotype)—6: ♀ (paratype). Scale 10 mm

FIGURES 7–9: habitus.—7 Oukhypencha stali n. sp. ♀ (holotype); 8–9: Homoiacoris annemarieae n. sp.—8: ♂ (holotype)— 9: ♀ (paratype). Scale 10 mm

FIGURES 19–23: Oukhypencha, female genitalia, evaporatoria.—19–22: female genitalia.—23: evaporatoria.—19, 23: Oukhypencha clemenceae n. sp.—20: Oukhypencha ophthalmica ophthalmica—21: Oukhypencha ophthalmica sumaterensis— 22: Oukhypencha stali. Abbreviations: ad—anterior duct, ev—evaporatoria field, ip—intermediate part, o—ostiole, pd—posterior duct, pw—posterior wall of vagina, r—receptacle, rs—ring sclerite, sd—striated dilation All scales 1 mm.

FIGURES 15–18: male genitalia, phallus and paramere—top: phallus (lateral view)—middle: ventral processus (ventral view, right side)—bottom: paramere (dorsal and lateral view, pilosity omitted in lateral view)—15 Hypencha sp. (same specimen as Fig. 10)—16: Oukhypencha clemenceae n. sp.—17: Oukhypencha florenceae n. sp.—18: Oukhypencha ophthalmica sumaterensis n. subsp. Abbreviations: a—apophysis, c—conjunctiva, d—membranous dorsal process, lv—latero-ventral processus, mv—membranous ventral process, ph—phallobase, sd—sclerified dorsal processus, sl—sensorial lobe, v—vesica, vp—ventral processus. All scales 1 mm.