Microditica Jordal

Jordal, Bjarte H., 2010, Revision of the genus Phloeoditica Schedl - with description of two new genera and two new species in Phloeosinini (Coleoptera, Curculionidae, Scolytinae), ZooKeys 56, pp. 141-156 : 151-153

Microditica Jordal gen. n.

Type species:

Microditica uniseriata Jordal, sp. n., monotypic.

Diagnosis.

Typical phloeosinine genus with a 5-segmented funicle, barely visible scutellum and the broadly separated pro- and mesocoxae. The genus is diagnosed by the unique long and laterally curved inner uncus (mucro) of the protibiae, by the deeply grooved antennal club, and by the short crenulations at the elytral base reaching only to interstriae 5.

Description:

Frons convex and nearly glabrous in both sexes; eyes entire; funicle 5-segmented, antennal club large, with deeply grooved sutures. Pronotum smooth and shiny. Scutellum very small, flush with elytra and mainly visible on anterior slope. Elytral base nearly straight, with a single row of crenulations from scutellum to interstriae 5. Metepisternal setae scale-like; sclerolepidia distinct, small. Protibiae with the inner uncus very large and curved laterally, lateral teeth apparently unsocketed. Hind wings with four setae along costal margin at stigmal patch, hind margin from base to tip with long setae. All coxae widely separated, mesosternal process vertical. Postnotum fused to metanotum, scutoscutellar suture parallel to sutural groove for two-third of its length, then curves relatively abruptly laterally. Proventriculus simple, without apical sutural teeth or posterior mastigatory brush. Male aedeagus weakly sclerotised, spiculum gastrale weakly forked and tegmen a simple ring.

Etymology.

The Greek name micro (small) refers to the small size of a bark boring beetle; ditica is a Latinised form of the Greek feminine adjective dytiké (that likes to penetrate) ( Alonso-Zarazaga and Lyal 2009).

Comments:

This genus shares most characteristics with Phloeoditica but is readily distinguished by the differently shaped protibia, the incomplete row of crenulations at the base of elytra, by the lack of ground vestiture, by the number and position of setae on the front and hind margin of the hind wings, and by the scutoscutellar suture following the scutellar grove much longer posteriad. The long setae along the hind margin are typical for small sized beetles ( Kuschel et al. 2000) and may not be of significant phylogenetic value. Phylogenetic analyses of combined COI and EF-1α nucleotide data show that Microditica and Phloeoditica are quite unrelated and do not necessarily form a monophyletic group (unpublished data). This taxon share a few characters with other tribes such as Phloeotribini (semiarticulated antennal club) and Hypoborini (interrupted row of crenulations at base of elytra), but is readily distinguished from all taxa in those tribes by the broadly separated coxae.