Scolytodes trigonus Jordal

Jordal, Bjarte H., 2013, New species and records of Scolytodes (Coleoptera, Curculionidae: Scolytinae) from South America, Zootaxa 3721 (6), pp. 529-551 : 546-547

Scolytodes trigonus Jordal , sp. nov.

urn:lsid:zoobank.org:act:0C98A70B-B76C-4939-B67D-356E4C7E0F16 ( Figs 39, 42, 45 )

Type material. Holotype, male: " Ecuador: Manabí Prov, Tabuga, Bosque Seco Lalo Loor, S00º04.916’ W80º09.029’, 101m, ex Cecropia leafstalk, 21–26.V.2011, S.M. Smith". Allotype and paratypes: same label as holotype (4 males, 6 females). Holotype, allotype and three paratypes in QCAZ. Two paratypes in USNM, two in ZMBN, and two in MSUC.

Diagnosis. Procoxae widely separated, protibiae broad, interstriae 10 sharply elevated far beyond level of metacoxae. Related to species in the S. maurus complex. Distinguished from all except S. brasilianus (Wood) , S. suturalis Wood and S. nitidissimus (Eggers) (= S. imitans [Eggers]) by the male frons having a transverse crest or callus just above the epistoma, and further from latter two species by the triangular shape of the impression above the crest. It has a shiny pronotum which is much more asperate in front, the lower frons is less rugosely punctured, and the body size is smaller and stouter compared to S. brasilianus .

Description male. Length 1.5–1.9 mm, 2.0 times longer than wide; colour dark brown to black. Head. Eyes separated above by 2.8 times their width. Frons weakly impressed in a triangular area from just below upper level of eyes and widening towards a transverse crest or callus (of variable height and sharpness) between antennal insertions; surface reticulate, with few moderately large punctures spaced by 1–2 times their diameter. Vestiture consisting of scattered fine setae arising from punctures. Antennal club with two slightly procurved sutures marked by short setae and some interspersed longer setae, suture 1 with a partial septum; segments 1 and 2 subcorneous, segment 3 strongly pilose. Funiculus 6-segmented. Submentum area weakly impressed. Pronotum as long as wide, widest at base, sides parallel on basal half, slightly constricted on anterior third, broadly rounded in front; surface smooth and weakly reticulate on posterior two thirds, distinctly asperate on anterior third, small distinct punctures reaching anterior margin, spaced on average by two times their diameter. Vestiture consisting of fine recumbent setae in asperate area and 8 erect longer bristle-like setae at anterior, lateral and posterior margins (4–2–2). Elytra 1.1 times longer than wide, 1.3 times longer than pronotum; sides straight on basal half, broadly rounded behind; stria 1 impressed from scutellum to apex, other striae weakly impressed; punctures mainly in rows, of two types in pairs, near contiguous, the smaller about one third to half the size of the larger puncture, each larger puncture spaced by 1–3 times their diameter; interstriae 3–4 times wider than striae, punctures few, tiny, with rows of tiny granules associated with base of each seta. Interstriae 10 reaching level of ventrite IV. Vestiture consisting of erect coarse interstrial setae from base to apex, spaced on posterior disc by less than length of a seta (frequently abraded on disc), some specimens with additional minute recumbent strial setae. Legs. Procoxae and metacoxae equally separated by 1.1–1.2 times the width of a procoxa. Protibiae broad, lateral tooth 2 extending beyond tooth 1, 4–5 additional smaller lateral spines towards tibial base, semitransparent cuticle extending lateral edge between tooth 2 and neighbouring smaller spines producing a broad tibial surface; protibial mucro strong, bent posterolaterally. Meso- and metatibiae with 7 lateral socketed teeth on distal half. Ventral vestiture. Mesanepisternum with 6–10 quadrifid setae, metanepisternum with few long simple setae.

Description female. Similar to male except asperities on pronotum less pronounced, frons is weakly concave from just below upper level of eyes to epistoma, widening gradually towards epistoma about half scapus length from inner eye margin; densely punctured in impressed area, above much less punctured and reticulate. Vestiture consisting of dense golden setae from punctures in impressed area, directed orad, none longer than scapus; minute setae from punctures above impressed area.

Key. The key leads to couplet 10, S. brasiliensis (Eggers) , but this species is actually more similar to S. brasilianus , see diagnosis above.

Etymology. From Latin trigonus , meaning ‘triangular’, referring to the triangular shape of the weakly impressed area of the male frons.

Biology and distribution. Known only from the type locality at the Ecuadorian Pacific lowland. Specimens were taken from the base of Cecropia leafstalks, together with the pith feeding S. fraterniatratus . All close relatives have the same host preference and breeding habits.

Figures

FIGURES 37 – 45. Dorsal, lateral and front view of Scolytodes solarius (37, 40, 43), S. fraterniatratus (38, 41, 44), S. trigonus (39, 42, 45).