Melanobaris troodi Stüben, 2024

Stüben, Peter E., Friedman, Ariel-Leib-Leonid & Braun, Christoph, 2024, A new endemic species of Baridinae (Coleoptera: Curculionidae) from the Mount Olympus on Cyprus, Israel Journal of Entomology (Oxford, England) 53 (6), pp. 131-152 : 135-146

Melanobaris troodi Stüben , n. sp.

( Figs 2 , 3 , 6 , 8 , 9 )

LSID: urn:lsid:zoobank.org:act:0C6D8F52-12A7-4C1C-8EF7-95DA76E0B0F4 .

Etymology: The species name refers to the host plant Odontarrhena troodi , endemic of the Troodos Mountains on Cyprus.

Diagnosis: The new Melanobaris species is—in terms of its morphology—closely related to two other species from the southeast of the Mediterranean Region: Baris amanicola Pic, 1905 from the Turkish Amanus Mountains extending along the Mediterranean coast, a species that was transferred to the genus Melanobaris by Korotyaev and Friedman (2011), and Melanobaris margaritae Korotyaev & Friedman, 2011 from Israel, described in the same publication.

In fact, the new species M. troodi described herein shares the body outline with M. amanicola , especially the strongly constricted area immediately behind the anterior margin of the pronotum ( Korotyaev &Friedman 2011: fig. 3). We acknowledge the excellent outline drawings of the aedeagus ( Korotyaev & Friedman 2011: figs 5, 6, 8), according to which, there is not even an approximate resemblance to the species from Cyprus described here. This is obviously also true for the isolated punctate pits on the flanks of the pronotum ( Korotyaev & Friedman 2011: fig. 1), which do not show any of the condensed puncture rows typical for M. troodi .

The habitus of the new species has much more in common with the endemic species M. margaritae from the Israeli part of the Hermon massif (south-western flank), which is known from an altitude of more than 1700 m a.s.l. However, the following differences in characteristics should be sufficient to distinguish the species morphologically (unfortunately, no molecular results are yet available for this species):

– The new species from Cyprus is—at the first glance—significantly larger, 3.5–4.0 mm (vs 2.9–3.5 mm);

– The pronotum is much more densely punctate, the deep punctures are more numerous ( Fig. 1 vs Fig. 4 );

– The deep punctures fused into rows on the sides of the pronotum is a remarkable feature (vs distinctly separate punctures in M. margaritae );

– Immediately behind the anterior margin of the pronotum the sides are rather suddenly strongly constricted; behind the constriction almost to the base subparallel (vs behind the front edge laterally significantly less constricted; the sides up to the base arcuate);

– Rostral dorsum noticeably humped and bulged at base; clearly visible in the females of M. troodi , Fig. 3 (vs rostrum without basal bulging, evenly curved in lateral view, Fig. 4 );

– Scutellum triangular (vs transverse and rectangular);

– Aedeagus with sides of median lobe slightly rounded (vs median lobe parallel-sided);

– Cornu, but especially collum (duct lobe) (swollen in M. troodi vs narrower in M. margaritae ) and ramus (gland lobe) (more humped, slightly slanted anteriorly in M. troodi vs less and evenly humped in M. margaritae ) of the spermatheca differently shaped ( Fig. 3 vs Fig. 5 ).

Another species—very similar to M. margaritae but also significantly larger—is the flightless M. gulnarae Korotyaev & Ismailova, 2011 with the host plant Matthiola daghestanica (Conti) N. Busch ( Brassicaceae ) from the northern Caucasus mountains of Inner Dagestan (Untsukulsky Distr.). However, this species has a matt upper side of the body, and a parallel-sided aedeagus with a strongly narrowed tip. In addition, the species is broader, especially the elytra (1.15–1.19× as long as the pronotum width!) in contrast to the slender habitus of M. troodi .

Description: The species is strikingly similar in many characteristics to Melanobaris margaritae Korotyaev & Friedman, 2011 . In order to avoid repetition, the description focuses primarily on the differences of the new species.

Body length 3.5–4.0 mm (without rostrum); body, including rostrum and appendages, shining pitch-black.

Head: Rostrum, that of males 3.3×, that of females 4.1× as long as wide between antennal insertions, almost parallel-sided, becoming abruptly somewhat narrower immediately near base; in lateral view strongly curved, hook-shaped, with hump-like obtuse bulge immediately near base (striking feature); more finely punctate dorsally, on sides of rostrum coarse punctures flow together into long and deep grooves; club-shaped scape of antennae about as long as funicle; 1 st antennomere (pedicel) ca. 1.2× as long as wide, following six antennomeres clearly wider than long and becoming subsequently wider towards barely separated, short-oval club.

Pronotum: As long as wide, densely punctate, with puncture spacing mostly of diameter of a long-oval puncture; on flanks punctures often only separated from each other by narrow ridges and form long and deep grooves (flowing together) towards underside; pronotum abruptly constricted immediately behind anterior margin (particularly pronounced in males); sides subparallel or straight, slightly converging and only more strongly incurved immediately near base.

Scutellum : Triangular.

Elytra: Elongate, 1.5–1.6× as long as wide, widest at end of basal quarter, rounded to elongate oval towards tip, with very narrow, groove-like striae and many times wider intervals with single row of punctures each; 7 th and 8 th striae end well before base.

Legs: Short, profemora just reach posterior margin of eyes, metafemora end far in front of elytral apex (at level of 4 th abdominal segment), densely punctate, each puncture with a fine, recumbent bristle.

Underside: Pro- and mesothorax with dense, deep pit-like punctures, only separated from each other by narrow ridges. The 1 st, long abdominal ventrite somewhat more densely (ca. half puncture diameter between punctures) and not quite as deeply punctate; following ventrites 2–4 with only very fine and sparse punctation, while ventrite 5 densely punctate and covered with short bristles apically. Abdominal ventrites 3 and 4 combined about as long as ventrite 2.

Aedeagus: With long median lobe oval rounded towards tip and slightly rounded laterally, evenly bent dorso-ventrally.

Female genitalia: Spermatheca, ovipositor (genocoxites and styli) and spiculum ventrale as in Fig. 3A–C .

Holotype: ♂ “ Cyprus, Olympos , Artemis Trail, 34°56’1”N 32°52’24”E, 1825 m, Alyssum troodi [ Odontarrhena troodi ], 11.11.2023, sifting, leg. Stüben (FO10)” ( SDEI), DNA (mtCO1) collector no. 4019-PST (see CO1-sequence in Appendix 2).

Paratypes: Cyprus: 2♀, same data as holotype, coll. Stüben ( SDEI) ; 1♀, same data as holotype, “ 13.11.2023 (FO15)”, coll. Stüben ; 2♀, same data as holotype, “ 11.3.2024 (FO 18)”, coll. Stüben ; 1♂, 2♀, “ CY – Lemesos, Troodos, Chionistre , 1900 m, 25.5.2023, under Alyssum troodi & cypricum , leg. Ch. Makris ”, coll. Makris, Stüben.

Distribution: Endemic to Cyprus.

Biology: This flightless and ground-dwelling species was sieved from under its supposedly host plant Odontarrhena troodi (Boiss.) (formerly Alyssum troodi ) ( Fig. 6 ). Ch. Makris (Limassol, Cyprus; pers. comm. 2023) also mentions Odontarrhena cyprica (Nyár.) (formerly Alyssum cypricum ) as a probable host. The adults stay mainly near the root collar, so they cannot usually be knocked off the 10–15 cm high, perennial semi-shrub and probably, therefore, remained undetected for a long time. In the insectarium, the species was only occasionally found on the plant itself.

The occurrence of the new species seems to be restricted to the summit area of Mt Olympus at 1825 m a.s.l. However, as the crucifer can also be found at lower altitudes above 1300 m, the occurrence of M. troodi should also be checked there. The larvae and pupae of the new species remain unknown to this day.

The only allied to M. troodi species of which the circumstances of its collection are known is M. margaritae on Mt Hermon ( Israel). Melanobaris margaritae is rarely collected and to date only eight specimens have been found, all on the top of Mt Hermon. All type specimens were collected at 2000 m a.s.l. The circumstances of the collecting of the older specimens in the 1970–1980s are unclear; however, they were most probably swept from the vegetation as both David G. Furth (Alticinae specialist) and the late dipterist Fini Kaplan were collecting nearly exclusively by sweeping, and it was unlikely they picked tiny weevils from the ground or dug them out of the soil. The two specimens found in 2010 were collected at the bottom of the Bol'an Valley ( Fig. 7 ) with pitfall traps – the weevils probably stayed near the root collar, similarly to M. troodi . On 2 March 2018, two additional specimens were found by the second author at 1700 m a.s.l., most probably by sieving fallen leaves as sweeping was impossible in that season.

We assume that the host plant of M. margaritae from Mt Hermon is related to that of M. troodi , belonging to the genus Odontarrhena C.A. Mey. or to the closely related genus Alyssum L.

Thirteen species of Alyssum have been recorded recently from Israel and the adjacent countries, mainly from high altitudes, both in the Mediterranean zone and in the desert (e.g. Mt Ramon in the Negev), with four species occurring on Mt Hermon (Danin & Fragman-Sapir 2024). Alyssum strigosum Banks & Sol. is widely distributed throughout the country; the other three species are found only on Mt Hermon at high altitudes: the very rare Alyssum baumgartnerianum Bornm. in the alpine tragacanth belt on the west-facing wind-beaten slopes; scarce Alyssum murale Waldst. & Kit. in the alpine tragacanth belt; and a slightly more common Alyssum szovitsianum Fisch. & C.A. Mey. occurring throughout Mt Hermon and in the northern and north-eastern parts of the Golan Heights. These three Alyssum species are potential hosts of M. margaritae ; in particular A. murale , which has been transferred from Alyssum to Odontarrhena ( Španiel et al. 2015; Royal Botanic Gardens Kew 2024) and, therefore, is the closest candidate to the assumed host of M. troodi ( Fig. 7 ).

DISCUSSION

Nineteen species of the crucifer-associated Baridinae living on Brassicaceae and Resedaceae , including seven Melanobaris species and 12 Aulacobaris species, have already been molecularly classified by Prena et al. (2021) according to a different subsection of the mtCO1 gene (819 bp) from that used here. Five winged species of Melanobaris ( M. morio , M. carbonaria (Boheman, 1836) , M. atramentaria (Boheman, 1836) , M. laticollis (Marsham, 1802) and Melanobaris sp. nr. laticollis ) appear monophyletic in the Bayesian tree, even with low support values, while M. erysimi and M. hochhuthi clustered paraphyletically in a subtree of Aulacobaris (with either A. lepidii (Germar, 1823) or A. ochsi (A. Hoffmann, 1950)) .

Twelve of a total of 30 Melanobaris species (15 of which are known from Europe) are barcoded here for the first time. The ‘Folmer region’, comprising standard base pairs in the CO1 gene and relatively well conserved, has been used for comparison for many decades and has a high variability to generate reliable results with a high differentiation potential at the species level ( Folmer et al. 1994).

In addition to the already barcoded Melanobaris atramentaria (Czech Rep.) , M. laticollis ( Poland) and M. carbonaria ( Slovakia) ( Schütte et al. 2013, 2023; Stüben et al. 2015), and thanks to Jens Prena who kindly furnished us with further species from various locations for sequencing, we were able to include another eight Melanobaris species: M. sinapis galliae (Tempère, 1961) ( France), M. steppensis (Roubal, 1935) ( Slovakia), M. cf. nigritarsis (Boheman, 1844) ( Romania), M. dalmatina (H. Brisout de Barneville, 1870) ( Greece), M. quadraticollis (Boheman, 1836) ( Italy), M. elevata (Reitter, 1899) ( Spain), and M. atronitens (Chevrolat, 1861) ( Morocco)—all determined by Jens Prena—and M. troodi n. sp. ( Cyprus)(Appendix 2). With another species Melanobaris morio (Boheman, 1844) (in Hendrich et al. 2015), our effort results in an unbalanced mtCO1 neighbour-joining tree (which includes 12 Melanobaris species occurring throughout Europe and partly also in Northern Africa and the Near East) ( Fig. 9 ), which does not take into account different mutation rates and back mutations, but which allows an initial assessment of phylogenetic relationships (especially at the species level).A Bayesian tree for 20 species of baridines associated with the Brassicaceae and Resedaceae with bootstrap support on branches is shown in Fig. 10 .

At present, we do not anticipate a revision of the Melanobaris species, which include black-coloured taxa that are difficult to distinguish morphologically, especially in Asia, because the molecular database and the number of species available to us are still too small. As in the study by Prena et al. (2021), a few metallic-blue Aulacobaris species, A. lepidii (mainly on Rorippa species) and A. picicornis (monophages on Reseda lutea L.), cluster paraphyletically in the otherwise already quite ‘monophyletic’ Melanobaris tree. The new species M. troodi from Cyprus appears as a sister taxon of M. elevata from Siles ( Spain), with the p-distance 13.83% ( Table 1). The overall morphological appearance of the Iberian species, which differs from M. troodi in the laterally strongly convex pronotum and the broadly rounded elytra, suggests that we are dealing with a more distantly related species ( Fig. 9 ), not only in geographical terms.

Unfortunately, the molecular characteristics of the morphologically considered (see the differential diagnosis above), closely related, also flightless (brachypterous) and endemic sister taxa from the neighbouring mainland of the Near East, M. amanicola and M. magaritae , are missing so far. This also applies to M. gulnarae described from the northern Caucasus mountains of Inner Dagestan. We suspect that these ground-dwelling species from very high altitudes in various mountain ranges are isolated endemics, which, with their strikingly slender habitus, probably fall into the species complex of Melanobaris dalmatina , whose type series possibly contains several species (J. Prena, pers. comm.). These very similar, sometimes even cryptic species can probably only be unambiguously identified through the molecular analysis.

And last but not least, the alleged proof of M. dalmatina in south-eastern Turkey (DiYarbakır province) and the hasty assumption that the species has recently spread on the Brassicaceae Myagrum perfoliatum L.( Özaslan & Bolu 2015) already appears highly questionable. Once again, it should be clearly emphasized that without knowledge of the type material and above all without a ‘molecular corroboration’, one should not embark on such thin ice of species identification, even in ecology.

Figures

Fig. 2.Holotype ofMelanobaris troodi n. sp., habitus (dorsal, lateral and ventral) and aedeagus (ventral and lateral).

Fig. 3. Paratype of Melanobaris troodi n. sp., habitus (dorsal and lateral) and female genitalia (A, spermatheca; B, ovipositor; C, spiculum ventrale).

Fig. 6. Summit region of Mt Olympus (‘Chionístra’) of the Troodos massif in Cyprus with the new baridine Melanobaris troodi and its supposedly host plant Odontarrhena troodi.

Fig. 8. 3D scan of the new species, a female of Melanobaris troodi (paratype) from Mt Olympus on Cyprus. Note: The 3D graphics can only be activated in the downloaded article.Then, click on the picture and allow 3D content if your PDF reader is asking you for permission (see info bar under the menu). Further information on the technical specifications of the scanner is provided in the Material and Methods section.

Fig. 9. Neighbour-joining tree for 12 Melanobaris species and 8 Aulacobaris species associated with Brassicaceae and Resedaceae.

Fig. 1. Powerful 3D scanners such as the DISC3D in the Museum Koenig (Bonn, Germany) will play an increasing role in the description of new species in entomology in the future. We have now made a start on this in weevil research at the Curculio Institute.

Fig. 4. Paratype of Melanobaris margaritae, habitus (dorsal and lateral) and aedeagus (ventral and lateral).

Fig. 5. Paratype of Melanobaris margaritae, habitus (dorsal, lateral and ventral) and female genitalia (A, spermatheca; B, ovipositor; C, spiculum ventrale).

Fig. 7. Mt Hermon (Israel) with last snowfields andthe Bol'an Valley in May 2019;the yellow cushions with Alyssum are clearly visible between the rocks (photos by A.L.L. Friedman). Below: Alyssum murale Waldst. & Kit., one of the potential host plants of M. margaritae (photos by Ori Fragman-Sapir, from Danon & Fragman-Sapir 2024).

Fig. 10. Bayesian 50% majority rule consensus tree built from mitochondrial CO1 for 20 species of baridines associated with Brassicaceae and Resedaceae (Appendix 2), with bootstrap support on branches. The analysis was run for 20 million generations.