Probosca (Proboxantha) coniuncta, Poloni, 2022

Poloni, Riccardo, 2022, The false-blister beetles (Coleoptera, Oedemeridae) of Oman with the description of a new species, Zootaxa 5162 (4), pp. 421-429 : 422-425

Probosca (Proboxantha) coniuncta n. sp.

( Figs. 1–3 )

Type locality. Oman Dhofar, Salalah, Taqah env., 4m // 17°02’04’’N 54°22’29’’E

Type Material. Holotypus, ♂ Oman Dhofar, Salalah // Taqah env., 4m // 17°02’04’’N 54°22’29’’E // 10.VII.2018, leg. I.Zappi ( RP). Paratypi, same locality, 1♂ 2♀ ( IZ), 3♂ 4♀ ( RP), 1♀ ( NMPC), 2♀ ( NHMO) ; Oman // Dzhophar prov. // Mirbat env. // 3.–4.X.2003, alt. 0–5m // St. Jakl leg., 1♂ 3♀ ( NMPC) 1♀ ( RP) ; Sultanate of Oman // Dhofar prov. // Taqah // 1.9.2007 / J. Horák leg., 2♀ ( NMPC) ; Oman, prov. Dhophar // Takwa env. VIII.1999 // S. Jakl lgt., at light, 3♀ ( NMPC) ; Oman mer. 1999 // Taqah, ca. 20–30m // 31.7.–11.8., at light // R. Červenka lgt., 1 ♀ ( NMPC) ; Oman: Ash Sharqiyah N. Gov. // Masirah Island , 26.x.2019, // Hiql vill. env.; wadi, at light, // 20°21.9’N 58°47.6’E, 5 m, // J.Hájek & A.Reiter lgt., 3♀ 3♂ ( NMPC), 1♀ 1♂ ( RP) ; Oman mer., // Darbaat // 18– 21.9.2003, // R. Červenka lgt., 2♀ 1♂ ( NMPC) ; Oman // Dhofar region // Dellacasa M. leg. /// Al Mughsayl dint. // 16°53’01N 53°46’47E // m 30 // 27.09.2001, 1♂ 3♀ ( MSNP) 3♀ ( RP) ; Oman — Dhofar // Rd. 49 Taqah dint. // m 10– 22.09.2001 // Dellacasa M. leg. 2 ♂ 1 ♀ ( MSNP).

Description.

Coloration: ( Fig. 1 ) head dark brown to black, mouthparts dark brown with the apical part of mandibles black, palpi rusty yellow with only the terminal part darkened, antennae rusty yellow with the first three segments lighter. Prothorax dark grey with a longitudinal keel dark brown, elytra dark grey with the sutural marginal lighter. Legs dark brown and progressively darkening towards the tarsi, which are dark brown with the articles darkened in their apical edge. Scutellum has the same colour of elytra. Abdomen dark grey, with the last segment rusty yellow.

Morphology. Head narrower than pronotum, eyes moderately protruding and slightly reniform. Space between eyes half of the head length and as large as the space between antennal bases. Head with regular and matt surface, with very small and irregular punctation. Pronotum slightly cordiform, the apical portion 1.5 times larger than the basal. Punctation sparse and deep, with a longitudinal keel in most specimens. Elytra regular, with almost straight sides, with an irregular punctation. Elytral apex moderately acuminate. Maxillary palpi with distal palpomere moderately securiform, antennae almost reaching elytral midlength, 11-segmented with the last segment narrowed in the apical half. Abdominal segments with a shallow and sparse punctation. Abdominal sternites and sclerites covered by a long and semi-erect white pubescence.

Pygidium widely rounded, last sternite slightly shorter than pygidium. Male genitalia ( Fig. 2 ) have a typical oedemeroid tegmen and aedeagus ( Švihla, 1985). The aedeagus is tubular, c-shaped and thickened in subapical portion. The basal apodeme is feebly developed. Tegmen is longer than aedeagus. Parameres are well developed, reaching approximately 1/3 of the length of the tegmen and carrying conspicuous setae.

Sexual dimorphism. Female with shorter antennae, elytra wider especially in posterior half and generally lighter pronotum.

Length: 6.2–8.9 mm

Variability. The male paratypes show marked variability ( Fig. 1a and 1c ). The colour in some specimens is in general darker or lighter, especially the longitudinal keel of the pronotum, legs, maxillary palpi and mandibles varying from rusty yellow to dark brown. The antennae vary between flavous to rusty yellow, with the antennomeres II–IV usually lighter than the others. The punctation of the pronotum can be more scattered and in some specimens is absent or very sparse in the longitudinal keel. The density of pubescence is also variable, with some specimens almost glabrous in the median part of the head and pronotum.

Etymology. From the Latin coniuncta = contemporary, agreeing, because this species was identified as new independently by the author and Vladimir Švihla, former curator of the National Museum of Prague, Czech Republic, and great taxonomist of Oedemeridae .

Differential diagnosis. The specimens from the new species were compared with the other species of the subgenus Proboxantha of the genus Probosca , in particular: Probosca (Proboxantha) fuscipennis , P. (Proboxantha) afroarabica , P. (Proboxantha) maindroni , P. (Proboxantha) marginata , P. (Proboxantha) comata , P. (Proboxantha) batesi and P. (Proboxantha) vanharteni . This species is quite different from the previous ones both in habitus and the male genitalia. The closest species are P. (Proboxantha) afroarabica ( Švihla, 1984) and P. (Proboxantha) maindroni (Pic, 1935) from which it differs by the dark brown integuments (lighter in the other two species) and shape of male terminalia, in particular the median lobe that differ from the other two similar species by the following characters: a) overall shape thinner and longer, b) apical portion slightly curved, c) sub-apical portion widened and d) shorter apex.

Taxonomic remarks. This species, according to the material at my disposal, must be ascribed to the subgenus Proboxantha Švihla, 1995 . The characters typical of this subgenus, according to Švihla (1985) are “body flavo-fuscous or partly metallic coloured, last segment of maxillary palpus securiform, pronotum cordiform to subcylindrical, depressions flat, surface of pronotum finely punctate, tegmen and aedeagus shorter than in Probosca s. str. ”. However, the heterogeneity of coloration and the structure of male genitalia do not allow a clear delimitation. The whole subgeneric classification of the genus Probosca probably needs detailed revision.

Ecology and distribution. This species, as many others of the genus, seems to be associated with salty ground and halophytic plants. My colleague Iuri Zappi, who collected part of the type series, observed the individuals feeding and mating on flowers in a sandy area about 200 meters from the seashore, in August. It is possible that the species as well as Probosca (Probosca) viridana feeds on halophylous plants. However, nothing has been published on the biology of the genus Probosca so far. The distribution is limited to the coastal areas of southern Oman in the region of Dhofar ( Fig. 3 ).

Figures

FIGURE 1. Probosca (Proboxantha) coniuncta n. sp., holotype male (a), paratype female (b), paratype male, variability (c).

FIGURE 2. Probosca (Proboxantha) coniuncta n. sp., aedeagus (a), tegmen (b)

FIGURE 3. Known distribution of Probosca (Proboxantha) coniuncta n. sp. Maps from Google satellite (left map, https:// google-satellite.gosur.com, last access 10/5/2022) and ESRI (www.arcgis.com, last access 10/5/2022).