Barretonus auarita García & Oromí, 2019

García, Rafael, Andújar, Carmelo, Oromí, Pedro, Emerson, Brent & López, Heriberto, 2019, The discovery of Barretonus (Curculionidae: Cossoninae) in the Canary Islands: barcoding, morphology and description of new species, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (2), pp. 443-452 : 447-449

Barretonus auarita García & Oromí , sp. nov.

( Figs 2 , 3A–G )

Type locality. Juan Adalid, Garafía, La Palma, Canary Islands (70 m a.s.l., 28°51′14.44″N, 17°54′25.43″W).

Type material. HOLOTYPE: 1 J, Juan Adalid, Garafía, La Palma, Canary Islands (70 m a.s.l., 28°51′14.44″N, 17°54′25.43″W), 3.i.2018, sieving Euphorbia balsamifera, R. García leg ( DZUL) . PARATYPES: 40 spec. from the same locality as the holotype: 2 ♀♀, 20.v.1992, R. García leg.; 2 ♀♀, 15.i.1994, P. Oromí leg.; 4 ♀♀ 13 JJ, 3.i.2018, R. García leg.; 14 ♀♀ 5 JJ, 15.v.2018, R. García leg. Depositories: AMC (1 J 1 ♀), CAF (1 J 1 ♀), HLH (1 J 1 ♀), IPNA-CSIC (1 J 1 ♀), JK (1 J 1 ♀), MCNT (1 J 1 ♀), MNCN (1 J 1 ♀), POM (2 JJ 2 ♀♀), PS (1 J 1 ♀), RGB (10 JJ 10 ♀♀).

Additional material examined. La Palma, El Granel, Playa de Nogales, 3 spec. (1 J 1♀ and 1 spec.), 16.iii.2018, sieving Crithmum maritimum, J. Krátký leg.

Description. Male. Total length (including rostrum) 2.45–2.90 mm. Maximal width 0.73–0.93 mm. Body yellowish-brown, vestiture glabrous, with tiny setae (2 μm), more visible on elytral striae, interstriae and edges of pronotum, setae longer on rostral apex, antennae and legs. Apterous.

Head sphero-conical, short, completely lacking eyes.

Rostrum (average length 0.44 mm), 0.64× as long as pronotum and 1.8× as long as its width at apex, with punctures and some setae; slightly curved in lateral view, dorsally with slightly concave sides in middle. Rostral surface and punctation similar to that on frons, the latter sometimes with small fovea; posterior part of rostrum convex in lateral view. Ventrally with two rows of punctures in middle zone and with two fine carinae converging towards base of rostrum.

Antennae pubescent; scape curved, widest in apical third, 4.5× as long as its maximum width and 0.85× as long as funicle. First funicular antennomere longest, cylindroconical, 1.25× as long as wide, funicular antennomeres 3 to 7 tronco-conical and transverse, narrower 2. Antennal club oval, 1.9× as long as wide and as long as antennomeres 6–7 combined.

Pronotum isodiametric, with slightly convex sides, widest in 1/3 of base, anterior edge 0.76× narrower than basal edge. Surface smooth and shiny, except on basal edge and lateral margins; with strong round punctures separated by 1× their diameter, punctures smaller and closely located at apices.

Scutellum not visible.

Pterothorax with elytra subparallel, base slightly concave and wider than pronotum, sometimes slightly sinuous in middle; 2.3× as long as pronotum and 1.86× as long as wide; striae composed of well marked but shallow punctures; interstriae on disc flat and slightly convex towards apical declivity, the latter short and steep with small aligned punctures. Metaventrite 2× as wide as long, slightly depressed on disc, with strong longitudinal furrow in apical zone.

Abdomen ventrally with microreticulated surface and round punctures separated by 2× their diameter. First two ventrites with convex disc, punctures more separated between them; fifth ventrite 2.25× as wide as long, with similar punctation as that on first two ventrites.

Legs with smooth, shiny surface and well defined punctation, covered by dispersed setae. Procoxae separated by 1.1× their diameter from anterior margin of pronotum and 0.15× their diameter from the posterior margin of pronotum; separated between each other by 0.14× procoxal diameter. Mesocoxae 2× their diameter apart. Pro-, meso- and metafemora respectively 3.3×, 3.1× and 3.7× as long as wide. Protibiae 3.25× as long as wide at apex (without counting uncus), almost straight, with external edge smooth and with dense strip of setae in slight inner apical notch. Meso- and metatibiae 3.53× and 4.3×, respectively, as long as wide. First tarsomere 2.5× longer than wide; second tarsomere isodiametric; third strongly bilobed and isodiametric; onychium 3.3× as long as wide.

Aedeagus. Tegmen without parameroid lobes and with short manubrium ( Fig. 3A ). Spiculum gastrale robust, with asymmetric arms, shorter arm less than half length of longer, longer arm with external lamella and shaft bent distally ( Fig. 3B ). Penis roughly symmetric in dorsal view, apex broadly triangular and briefly pointed, laterally with one side concave and the other one convex; slightly curved in lateral view, with acute apex and small callus; dorsal plate incomplete; internal sac with densely arranged teeth in apical third of tube ( Figs 3C–D ).

Female. Very similar to male, total length 2.15–2.6 mm, maximal width 0.75–0.86 mm. Rostrum 2.44× as long as wide. Scape 3.7× as long as wide, widening from middle; funicular antennomeres 6 and 7 wider than 1. Elytra 2.32× as long as pronotum, 1.64× as long as wide. 5 th ventrite 2.83× as wide as long. Pro-, meso- and metafemora respectively 3.1×, 3× and 3.4× as long as wide. Pro-, meso- and metatibiae respectively 3.2×, 3.1× and 3.4× as long as wide.

Ovipositor with conical apical styles, bearing 4–5 macrosetae ( Fig. 3F ). Spiculum ventrale bilobed bearing about 17 macrosetae ( Fig. 3E ); manubrium long, straight, with small unilateral termination. Spermatheca narrow, with curved cornu and hardly developed glandular lobe ( Fig. 3G ).

Differential diagnosis. For comparison with B. daute sp. nov., see Table 2.

Etymology. The specific epithet auarita refers to the auaritas, the aboriginal people inhabiting La Palma before the colonization by Europeans. Noun in apposition.

Biology and ecology. All specimens from Juan Adalid were collected at about 20 m a.s.l., in a partially well preserved coastal scrub ( Euphorbia balsamifera Aiton ) with northern orientation. The first specimens collected were four females in the 1990s, found inside the dead roots of E. balsamifera . The same site was subsequently visited on numerous occasions in search for males to describe this new species, but with no success. The largest series was obtained recently by screening decaying roots of E. balsamifera . One of the specimens was immature and collected inside its pupal chamber, so at least we know where larvae of this species develop and that the nutritious plant certainly is Euphorbia balsamifera . In comparison, samples from Playa de Nogales were collected recently by sifting decaying litter of Crithmum maritimum , a plant where other endogean curculionids such as Styphloderes lindbergi Roudier, 1963 and Madeiran Barretonus were also collected. One of the females from Juan Adalid was dissected, and one oval egg measuring 0.5 × 0.4 mm was found inside its abdomen.

Figures

Fig. 2. Dorsal and lateral habitus: A – Barretonus auarita sp. nov.; B – B. daute sp. nov.

Fig. 3. Structures of the genitalia of males and females of B. auarita sp. nov. (letters without asterisks) and B. daute sp. nov. (letters with asterisks):A – tegmen. B – spiculum gastrale. C–D – aedeagus in dorsal and lateral view. E – spiculum ventrale. F – ovipositor. G – spermatheca.