Ctonoxylon quadrispinum, Jordal, 2024

Jordal, Bjarte H., 2024, An integrated taxonomic revision of Ctonoxylon (Coleoptera, Curculionidae, Scolytinae) reveals new Malagasy species originating from multiple recent colonisations of the island, ZooKeys 1203, pp. 95-130 : 95-130

Ctonoxylon quadrispinum sp. nov.

Figs 66 , 69 , 72

Type material.

Holotype, female: Madagascar, Ankarafantsika NP [GIS: - 16.264, 46.828], 200 m alt., 8. 5. 2015, ex liana, B. Jordal, leg. [ ZMUB] . Paratypes: same data as holotype [ NHMW, ZMUB] .

Diagnosis.

Anterior teeth on the pronotum quadrifid; lateral anterior margin of prothorax with elongated groove; propleural pit present; scutellar shield detached; elytral suture strongly curved just behind scutellar shield, a little buckled further behind.

Description.

Female. Body length 2.6–3.0 mm, 2.1 × as long as broad; immature colour pale brown. Frons convex, surface reticulate, vestiture consisting of sparse, short setae. Eyes divided, each part separated by 2 / 3 the size of upper half. Antennal funiculus 7 - segmented; club with two asymmetrically and strongly procurved sutures, suture one more distinctly marked, with a dark partial septum along its front margin. Pronotum broadly asperate on anterior two-thirds, anterior margin with pair of two bifid raised teeth (quadrifid). Anterior lateral margin of prothorax with pointed eye scraper at level of eyes, a deep groove from this point to coxa; a transverse propleural groove located between coxa and lateral costa on pronotum. Scutellar shield detached from elytra. Elytral suture strongly curved immediately behind scutellar shield and slightly buckled at midlength; striae strongly impressed, punctures round, large and deep, spaced by their diameter or less; interstriae raised, vestiture consisting of irregular and partly confused rows of short scale-like setae, with ground vestiture consisting of shorter setae of the same type and density; apex slightly emarginated. Metanepisternum and metaventrite with scant simple setae; last abdominal ventrite with small concavity. Protibiae on anterior face with groove for reception of tarsus as deep as width of tibia.

Male nearly identical to female, except frons impunctate and glabrous in a narrow band from epistoma to upper level of eyes, front teeth along the pronotal margin very slightly behind the position in females, and last abdominal ventrite flat.

Etymology.

Composed by the Latin prefix quadri - meaning four, and the Latin adjective spinum in its neuter form derived from spina, meaning thorn, referring to the four sharp teeth along the front margin of the pronotum.

Distribution and biology.

Only known from the type locality in Madagascar where broods containing pupae and tenerals, but not parents, were collected from a liana 4 cm in diameter, with thick bark. Egg tunnels were biramous and cut transversely to the grain. Brood sizes ranged from 50–60 (n = 20).

Figures

Figures 66–74. Dorsal, lateral, and front views of 66, 69, 72 Ctonoxylon quadrispinum female holotype 67, 70, 73 Ctonoxylon methneri male, and 68, 71, 74 Ctonoxylon atrum female holotype.