Catomus aeolicus, Ponel & Cascio & Soldati, 2020

Ponel, Philippe, Cascio, Pietro Lo & Soldati, Fabien, 2020, A new species of Catomus Allard, 1876 (Coleoptera: Tenebrionidae: Helopini) from the Aeolian archipelago (Sicily, Italy), Zootaxa 4743 (2), pp. 295-300 : 296-298

Catomus aeolicus sp. nov. ( Figs 1A, 1B, 1C )

Description. Male ( Fig 1A ). Body length from epistome to elytral apex 4.0– 7.3 mm. Entirely black brown, without any metallic shine, antennae and legs paler; entirely glabrous on dorsal side, ventrites covered with very short, scattered, whitish setae, antennae and legs with dense, whitish pubescence; head and pronotum shiny although densely punctuate, elytra dull and alutaceous; body elongated, pterothorax oval; wingless.

Head. Strongly and densely punctuate, punctures as large as or larger than areas between them, elongated, sometimes almost confluent and forming short striae, subrounded on head sides and behind vertex, intervals with fine microreticulation visible at strong magnification (x50); epistome straight, truncate, separated from vertex by a transverse depression, eyes prominent, appearing rounded when viewed from above, oval in lateral view, not notched by epistome or by antennal insertion; without short vertical groove from bottom edge of the eyes; last maxillary palpomere strongly securiform; labial palpi with last palpomere enlarged but not securiform; antennae long, exceeding posteriad the middle of elytra by at least one antennomere, first antennomere strongly clavate, second transverse, third to seventh elongated, especially the third which is three times longer than broad, slightly enlarged from base to apex, eighth to eleventh distinctly flattened, enlarged from base to apex, last one reniform.

Pronotum. 1.2 times broader than long, anterior angles rounded but marked, posterior angles completely obsolete, totally rounded, pronotum widest prior middle, puncturation coarse and dense on disc (similar to that of the head), less dense and coarse laterally; punctures elongated, sometimes almost confluent and forming short striae, space between them with fine microreticulation visible at higher magnification (x50), similar to that on head; pronotum entirely and finely rimmed, the middle third of front margin excepted.

Elytra. Oval, looking more dull and alutaceous than head and pronotum due to a finer and denser microreticulation; humeri entirely rounded, humeral callus absent; all striae narrow and deep, deeper at base, punctuate, punctures slightly broader than striae, slightly notching interstriae; the latter regularly convex from base to apex; cuticle on interstriae surface apparently smooth but, at higher magnification (x50), covered with sparse superficial punctures; scutellum broad, dull and smooth.

Ventral side. Prohypomera dull, impunctuate, with longitudinal wrinkles; head, prosternum, mesoventrite and metaventrite punctuate, punctures stronger and denser on mesoventrite; all ventrites finely punctuate, each puncture bearing a fine and short whitish seta.

Legs. All tibiae bent, mesotibiae stronger so; male protarsi strongly widened, first to third tarsomeres, taken together, two times longer than broad and much wider than apex of protibiae; mesotarsi less widened, first to third tarsomeres, taken together, almost three times longer than broad; metatarsi simple; all tarsomeres with sparse whitish setae on upper surface, first to fourth tarsomeres of protarsi and mesotarsi covered with a dense whitish pubescence on inferior surface, tarsomeres of metatarsi simple; onychium simple.

Aedeagus ( Fig 1C ). Parameres four times shorter than phallobase, tapering from base to apex, acuminate, without constriction between phallobase and parameres; inner margin of parameres very slightly sinuate, phallus very parallel with simple rounded apex.

Female ( Fig 1B ). Body length from epistome to elytral apex 4.8–8.2 mm. Pronotum less shiny, more strongly microreticulate, punctures finer, punctation sparser; antennae shorter, hardly reaching the anterior fifth of elytra, eighth to eleventh antennomeres indistinctly flattened, slightly enlarged from base to apex; all tibiae bent as in males; pro-, meso- and metatarsi simple, not widened, lower surface without any thick whitish pubescence sole.

Diagnosis. Catomus aeolicus sp. nov. can be easily separated from the other European Catomus species by its strongly bent mesotibiae, unusually widened male protarsi, long male antennae and shape of its aedeagus ( Fig. 1C ). By its long antennae this species most closely resembles C. fallax ( Vauloger, 1900) from Tunisia and Libya, which belongs to the same group. But the latter differs by having less punctuate pronotum, smooth and hardly punctuate striae on elytra, more plane interstriae in both sexes, prohypomera with scarce and large punctures. Furthermore, male protarsi are not so enlarged as in the new species.

Variability. The new species displays well marked sexual dimorphism in morphology of antennae and legs. The size of specimens is extremely variable: in the studied material the smaller ♂ is only 4.0 mm long, whereas the larger ♀ reaches 8.2 mm. The color ranges from very dark to reddish, the latter probably corresponding to teneral specimens. Furthermore, the average size in the specimens from Stromboli (9 ♂♂: m = 6.03 mm, s.d. = 0.95; 6 ♀♀: m = 7.21 mm, s.d. = 0.72) is larger than in those from Panarea (28 ♂♂: m = 5.05 mm, s.d. = 0.69; 11 ♀♀: m = 6.05 mm, s.d. = 1.15).

Type material. Holotype ♂, labelled: “SICILE-EOLIENNES, île Panarea, 7-XI-2015, P. Ponel leg.” (white label); “ Holotype ♂, Catomus aeolicus sp. nov., P. Ponel, P. Lo Cascio & F. Soldati ” (red label), Muséum National d’Histoire Naturelle, Paris.

Allotype ♀, labelled: “SICILE-EOLIENNES, île Panarea, 7-XI-2015, P. Ponel leg.” (white label); “ Allotype ♀, Catomus aeolicus sp. nov., P. Ponel, P. Lo Cascio & F. Soldati ” (red label), Muséum National d’Histoire Naturelle, Paris.

Paratypes: 6 ♂♂ and 3 ♀♀, same data as Holotype ; 3 ♂♂ and 2 ♀♀, “SICILE-EOLIENNES, île Stromboli, 8-XI- 2015, P. Ponel leg.” ; 21 ♂♂ and 7 ♀♀, “SICILE-EOLIENNES, île Panarea, 7-XI-2016, P. Ponel leg.” ; 6 ♂♂ and 4 ♀♀, “STROMBOLI: Nel Cannestrà, beating Spartium junceum , XII-2016 leg. P. Lo Cascio ”. All paratypes have a red label: “ Paratype ♂ (or ♀), Catomus aeolicus sp. nov., P. Ponel, P. Lo Cascio & F. Soldati” . Paratypes are deposited in the author’s collections P. Ponel, P. Lo Cascio and F. Soldati, as well as in the Piero Leo collection (Cagliari) and the Zoological Museum of the Università degli Studi di Firenze “La Specola” .

Etymology. The name aeolicus is an adjective derived from this group of islands, named after Aeolus (in ancient Greek Αιολός), the god of the winds.

Ecology. All the specimens of Catomus aeolicus sp. nov. were collected by beating old woody shrubs with dehiscent bark, especially the Spanish broom Spartium junceum L. and other Fabaceae , but the species has been found also on old branches of lentisk Pistacia lentiscus L.

Figures

FIGURE 1. Catomus aeolicus sp. nov. from Panarea,Aeolian archipelago, Sicily.A, habitus, male holotype, length: 5.3 mm. B, habitus, female allotype, length: 5.5 mm. C, aedeagus in lateral view (left) and ventral view from below (middle), right: phallus separated from the tegmen. D, the Aeolian archipelago, in black: islands occupied by Catomus aeolicus sp. nov. (from Wikimedia, modified). Scale bars: 1 mm.