Orthomus ( Nesorthomus ) bedelianus isambertoi Serrano & Boieiro, 2025
publication ID |
https://doi.org/10.11646/zootaxa.5683.3.4 |
publication LSID |
lsid:zoobank.org:pub:7FC69878-B546-4975-B818-4D58ADD4E61B |
DOI |
https://doi.org/10.5281/zenodo.17016160 |
persistent identifier |
https://treatment.plazi.org/id/03AC87E9-4549-FF8E-FF57-B45FFAD90BD9 |
treatment provided by |
Plazi |
scientific name |
Orthomus ( Nesorthomus ) bedelianus isambertoi Serrano & Boieiro |
status |
subsp. nov. |
Orthomus ( Nesorthomus) bedelianus isambertoi Serrano & Boieiro ssp. nov.
( Figs 2c View FIGURE 2 , 3 View FIGURE 3 and 4 View FIGURE 4 )
Type material: Holotype male: “Bugio Planalto S.\Desertas 18.XI.2015 \ I. Silva leg.” \\ “ Holotype male\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], ASC ; Paratypes, same locality as holotype, paratype male: “Bugio Planalto S.\Desertas 27.IV.2011 \ I. Silva & A. Serrano leg.” \\ “ Paratype male\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], 2 paratypes females : “Bugio Planalto S.\Desertas 27.IV.2011 \ I. Silva & A. Serrano leg.” \\ “ Paratype female\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], 1 paratype female : “Bugio Planalto S.\Desertas 15.IV.2012 \ I. Silva leg.” \\ “ Paratype female\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], 4 paratypes males : “Bugio Planalto S.\Desertas 18.XI.2015 \ I. Silva & A. Serrano leg.” \\ “ Paratype male\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], 3 paratypes females : “Bugio Planalto S.\Desertas 18.XI.2015 \ I. Silva & A. Serrano leg.” \\ “ Paratype female\ Orthomus ( Nesorthomus) \ bedelianus isambertoi ssp. nov. \ A. Serrano & M. Boieiro det. 2024” [t] [h] [red card], ( ASC: 4 males, 5 females; MMF: 1 male, 1 female) .
Etymology. The subspecific epithet isambertoi is used as a noun in apposition based on the name of Isamberto Silva, the ranger of the Parque Natural da Madeira who collected the majority of the specimens and called our attention to this ground beetle. We are pleased to name this subspecies in his honour.
Diagnosis. Apterous, general aspect amaroid, depressed and blackish-colored ( Figs 2c View FIGURE 2 , 3a and 3c View FIGURE 3 ); integument microreticulate, glabrous. Elytron with two discal setae, the anterior inserted very close or on third stria and the posterior close or on second stria. Male mesotibiae strongly arcuate, third apical inner margin strongly dilated before apex ( Fig. 3a View FIGURE 3 ); metatibiae slightly arcuate, third apical inner margin dilated ( Fig. 3a View FIGURE 3 ). Female abdominal sterna 3 to 4 with a slight lateral concavity on each side ( Fig. 3d View FIGURE 3 ). Aedeagus with median lobe strongly arched, slightly constricted between basal bulb and shaft ( Fig. 4a View FIGURE 4 ); basal lobe with slight prominent apophysis ( Fig. 4a View FIGURE 4 ); apical plate flat, largely triangular, slightly inclined leftward and upward ( Fig. 4b View FIGURE 4 ).
Description.Length of holotype:13.5mm.Length of paratypes:13.0–14.3 mm(males), 12.2–13.8mm(females). Head, pronotum and elytra blackish, rarely rufopiceous, shiny; antennae, palpi and legs slightly paler; dorsal surface of isodiametric meshes on head, pronotum and elytra, more faintly on head and pronotum, micropunctures on head and pronotum, denser and deeply impressed on the former.
Head ( Figs 3a and 3c View FIGURE 3 ) slightly wider than long [length: 1.95–2.27 mm (males) and 1.70–2.24 mm (females), width: 2.40–2.74 mm (males) and 2.40–2.78 mm (females)], eyes only slightly prominent, tempora pronounced, two juxtaorbital sensorial setae near both eyes. Labrum transverse, similar in male and female, with six setae near forward edge; one pair of clypeal setae. Antennae typical for genus, reaching the basal one-third of elytra when extended backwards.
Pronotum ( Figs 3a and 3c View FIGURE 3 ) typically trapezoidal, the widest part between the posterior angles, almost twice wider than long (males: 1.7 times, females: 1.8 times) [length: 2.84–3.17 mm (males) and 2.81–3.10 mm (females), width: 4.95–5.45 (males) and 4.95–5.64 mm (females)], disk flattened, depressed between the two distinct basolateral fovea, these and the hind angles faintly punctured, even lesser on the latter, medial longitudinal sulcus deep and well defined, not reaching the anterior and the posterior margins; front angles very prominent, notch of front margin slightly pronounced; posterior margin almost straight, slightly arched near the basolateral fovea; lateral margins slightly divergent just anterior to hind angles, slightly rounded in the first two thirds; prosternum glabrous; surface of isodiametric meshes on pro, meso and metepisterna, sparsely micropunctured on the former, finely punctate on the latter ones. One pair of lateral setae close to the margin in the end of the first third, one pair of basolateral setae closer to the posterior margin than to the lateral margin.
Elytron ( Figs 3a and 3c View FIGURE 3 ) 1.2–1.4 times longer than wide [length: 7.59–8.38 mm (males) and 7.19–7.99 mm (females), width: 5.54–6.14 (males) and 5.54–6.47 mm (females)] flattened, sub-parallel, the greatest width at the first third, progressively narrowing towards apex; humeral angle identate. Striae thin, well-marked, not punctured; scutellar striole well developed, with a basal seta close to the second stria; intervals slightly convex, first and second equals, third to seventh slightly wider, the eighth wider than the others; interval 3 with two setiferous pore punctures, one in the basal third close or on the third striae, the other in the middle third close or on the second striae. Umbilicate series with a humeral group of six setae, an intermediate single seta followed by 9–10 setae and an apical seta. Lateral groove well-marked, mainly indicated in the anterior third; lateral margin very slightly sinuate in the middle region, both in males and females, deep subapical sinuation in males and females. First four tarsomeres of male protarsus dilated, the fourth less dilated, all triangular, with two longitudinal rows of adhesive seta; mesotibiae strongly arcuate, apical third of inner margin strongly dilated before apex; metatibiae arcuate, apical third of inner margin dilated.
Abdomen with sterna 3 to 5 each with one pair of posterior paramedial setae, sixth visible sternum with one pair of paramedial setae in males, two in females; female abdominal sterna 3 to 5 with a slight lateral concavity on each side ( Fig. 3d View FIGURE 3 ).
Aedeagus ( Figs 4a and b View FIGURE 4 ) with median lobe strongly arched, slightly constricted between basal bulb and shaft ( Fig. 4a View FIGURE 4 ); basal lobe with slight prominent apophysis ( Fig. 4a View FIGURE 4 ); apical plate flat, largely triangular, slightly inclined leftward and upward ( Fig. 4b View FIGURE 4 ).
Female genitalia (not shown) with gonostylus sharp, sickle–shaped, with a sub–terminal fovea that bears two long, thin setae; latero–ventral and latero-dorsal sides with one thorn-like setae, respectively; gonocoxite triangular, without setae at base; hemisternite aliform with 8–9 thick, thorn–like setae at posterior margin.
Sexual dimorphism. Like other Orthomus ( Nesorthomus) species (see Serrano et al. 2009), the males of the new subspecies are slightly larger than females (see ranges in the description). The dimorphism of anterior tarsomeres follows the pattern of the genus: the first three tarsomeres are much more dilated in males than in females (cf. Figs 3a and 3c View FIGURE 3 ). Male mesotibiae are strongly arcuate, with third apical inner margin strongly dilated, and metatibiae slightly arcuate, with third apical inner margin also dilated ( Fig. 3a View FIGURE 3 ). These traits are quite different in females. Unlike the pronounced dimorphism observed in Orthomus ( Nesorthomus) annae (Donabauer) , where females exhibit a prominent lateral concavity on the visible abdominal sterna 3 and 4 (a feature absent in males), this trait is nearly imperceptible in the new subspecies [cf. Fig. 4D View FIGURE 4 in Serrano et al. (2009) and Fig. 3d View FIGURE 3 ] The dimorphism on the number of pairs of sub–apical paramedial setae on the sixth visible sternite follows the pattern of the subgenus, with one pair in males and two pairs in females.
Taxonomic remarks. The new subspecies belongs to the Nesorthomus subgenus since it has a short and punctuated metepisterna. Seven species out of the eight known within Nesorthomus subgenus are easily segregated from the new taxon regarding external features, such as body size, localization of elytral setiferous pore punctures, mesotibia and metatibia features, abdominal concavities on sterna and male aedeagi (see Serrano et al. 2009). The new taxon is akin to Orthomus ( Nesorthomus) bedelianus (Lutshnik) by external features and aedeagus type ( Figs 3b View FIGURE 3 and 4 View FIGURE 4 c-d), but it is well differentiated from this subspecies by the shorter length of the median lobe of aedeagus (4.4–4.7 mm vs 4.0–4.4 mm; t=3.93, p<0.01) and the shape of the aedeagus apex (see Figs 4a–b and 4c–d View FIGURE 4 ). Moreover, despite their morphological similarities, the new subspecies is larger than the nominal subspecies, showing on average a larger pronotum and elytra width (pronotum width: 5.0–5.6 mm vs 4.7–5.2 mm; t=4.44, p<0.001 elytra width: 5.5–6.5 mm vs 5.3–5.7 mm t=4.06, p<0.001).
The general structure pattern of O. bedelianus isambertoi ssp. nov. female genitalia is similar to that of the Orthomus ( s.str.) species (see Ortuño 1996; Serrano et al. 2009). The gonostylus in the new subspecies bears three thorn-like setae, like some Orthomus ( s.str.) species and O. ( Wolltinerfia ) spp. (see Machado 1992). A consistent feature is the absence of setae at the base of gonocoxite. The new subspecies presents 8–9 thick thorn–like setae at the posterior margin of hemisternite, a number that falls within the range (5–15) found in the Orthomus ( s. str.) spp.
The distinct and consistent differences in the male median lobe of the aedeagus between the Desertas specimens and the Madeiran ones, combined with the insular isolation (allopatry) of the Desertas population, provide support to classify this population as a distinct subspecies. The differences seen in the median lobe are likely a case of allopatric speciation in a relict population on the island of Bugio.
Collecting observations and distribution. The entomological expeditions carried out to the Desertas Islands explored especially Deserta Grande and Ilhéu Chão ( Wollaston 1857; Colas & Mateu 1958; Quartau 1981; Serrano 1987; Erber & Hinterseher 1988) since Bugio is a very steep island, difficult to access ( Fig. 1a View FIGURE 1 ). The recent discovery of Orthomus specimens in Bugio followed the construction of facilities by “Serviço do Parque Natural da Madeira ” (SPNM) to support the observation and monitoring of nesting seabirds (e.g., Pterodroma deserta ). This fact led to the discovery of this ground beetle on the easternmost cliffs close to the small plateau in the extreme south of this island ( Fig. 1c View FIGURE 1 ). The adults of this subspecies were firstly discovered and captured beneath stones by means of direct prospection by the SPNM ranger Isamberto Silva. Later, it was found that O. bedelianus isambertoi ssp. nov. appears to be restricted to those easternmost slopes of the island, as it was never found on the plateau. Other ground beetle species (e.g., Scarites abbreviatus desertarum , Harpalus attenuatus , Nesarpalus gregarius , Calathus complanatus vandeli ) were collected close to the new subspecies on the plateau. The new subspecies apparently presents a very restricted distribution, thus deserving special protection status and population monitoring.
MMF |
Museu Municipal do Funchal |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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