Microcosmoderes Johnson and Jordal

Johnson, Andrew J., Hulcr, Jiri, Knížek, Miloš, Atkinson, Thomas H., Mandelshtam, Michail Yu., Smith, Sarah M., Cognato, Anthony I., Park, Sangwook, Li, You & Jordal, Bjarte H., 2020, Revision of the Bark Beetle Genera Within the Former Cryphalini (Curculionidae: Scolytinae), Insect Systematics and Diversity 4 (3), No. 1, pp. 1-81 : 39-40

Microcosmoderes Johnson and Jordal gen. nov.

( Fig. 20 )

(LSID: urn:lsid:zoobank.org:act:9503C4F2-A4A1-4BAB-9EB6-8C5061CD118A )

Type of genus

Ptilopodius shoreae Schedl, 1953: 293 .

Diagnosis

Microcosmoderes can be diagnosed from other Trypophloeini genera by the rounded apical margin of the pronotum (without marginal asperities), by the males with fully developed wings, the proventriculus with a very long and saw-toothed apical plate, a cylindrical third tarsal segment, and the antennal club with one faint suture.

Female

Eye very weakly emarginated. Frons with a transverse, short, barely visible carina just below level of eyes. Cuticle behind eyes with weakly visible striations. Antennae with four funicle segments. Antennal club flattened and round; posterior face with a single, weakly indicated procurved suture; anterior face with a transverse suture near base. Anterior margin of the pronotum smooth, numerous asperities behind margin towards a slightly elevated summit. Pronotal disc coarsely punctured near to summit; a weakly visible carina at the base of the lateral margin only. Elytra convex, without distinct sculpturing. Interstrial bristles slightly flattened and spatulashaped. Interstrial ground vestiture absent. Proventriculus: apical plate longer than posterior plate, without median suture, with about 15 recurved sharp edges containing many small sharp teeth; closing teeth branched at tips, femoral teeth long and abundant.

Male

Similar to female with no apparent external sexual dimorphism. Penis apodemes of a similar length or longer than penis body, separated at apex. Tegmen open dorsally, with a median ventral apodeme nearly as long as penis apodemes. Spiculum gastrale slightly thicker than penis apodemes, with a weak fork. Basal sclerites visible.

Distribution

Peninsular Malaysia to Borneo.

Etymology

The name is composed by the Latinized form of Greek adjective mikros, meaning small, and the name of the related genus Cosmoderes in reference its morphological similarity to this genus. Gender masculine.

Remarks

Monotypic. Microcosmoderes was previously determined as a Ptilopodius (= Eidophelus ) sp. following Wood’s key to genera and used with that designation ( Jordal and Cognato 2012, Pistone et al. 2018). The biology of this genus is not known; the species was found in a small twig. Browne (1961) notes that the species is inbreeding (similar to Hypothenemus ), but we studied a male which had functional eyes and wings which suggest that males disperse and mate outside the parental gallery (typical of an outbreeding species). Based on Browne’s inferred habits of this species ( Browne 1961), it is likely that it feeds gregariously, a trait correlated with, but not limited to, inbreeding in bark beetles ( Kirkendall 1983, Jordal and Cognato 2012, Johnson et al. 2018).

Type material examined

Holotype of Ptilopodius shoreae Schedl, 1953 ( BMNH).

Included species

Microcosmoderes shoreae ( Schedl, 1953b: 293) (Ptilopodius) comb. nov. [ Ptilopodius ].

Figures

Figure 20. Images of Microcosmoderes shoreae: A) Lateral, dorsal, and ventral photograph, B) frons, and C) proventriculus.