Agrilus duffelsorum sp. nov.

(Figs. 1F, 5E)

Description of holotype. Size: 3.9 mm. Body. Shape: cuneiform; Build: robust; Posterior tapering part: short with broad apex; Profile: convex; Color (dorsally): unicolored. Head. Size: very large; Medial impression: absent. Vertex: Sculpture elements: rugae; Sculpture aspect: arcuate; Sculpture density: dense; Sculpture intensity: rough. Eyes: Size: subequal to half width of vertex (dorsal view); Lower margin: in line or below antennal socket; Median orbit: subparallel. Antennae: Serration: from antennomere 4. Pronotum. Shape: visually transverse; Sides: slightly arcuate; Maximal width: at middle; Anterior margin: narrower than posterior. Anterior lobe: Development: moderate; Shape: arcuate; Position: projecting beyond anterior angles. Posterior angles: Shape: rectangular; Apex: blunt. Disk: Convexity: strongly convex; Impressions: absent. Prehumerus: Development: absent. Lateral carinae: Convergence: moderate; Junction: present; Narrowest point: at posterior 1/5–1/4 of marginal carina. Scutellum: Size: robust. Elytra. Color: unicolored; Humeral carina: absent. Apices: Arrangement: conjoint; Shape: subtruncate; Truncation: oblique with projecting sutural angle. Pubescence: Color: unicolored; Extent: proximal and distal; Proximal (shape): quadrangular; Distal (shape): apical. Sternum. Prosternal lobe: Size: narrow; Distal margin: arcuately emarginate; Emargination (depth): shallow; Emargination (width): wide. Prosternal process: Shape: subparallel; Sides: straight; Angles: obtuse; Disc: impressed; Projection (length): protruding distinctly beyond angles. Metasternum: Metasternal projection: impressed. Abdomen. Pygidium: Apical margin: arcuate. Last ventrite: Disk: impressed. Sternal groove: Extent: on apical ventrite; Shape on apex of last ventrite: arcuately sinuate; Sinuosity (delimitation): angulate. Legs. Metatarsus: Length to metatibia: distinctly shorter. Tarsomere 1: Length to following tarsomeres: shorter or subequal to 2–3. Genitalia. Aedeagus (Fig. 5E): Symmetry: symmetric; Shape: widest in apical part; Profile: convex.

Variability. Unknown. Sexual dimorphism. The male has two tubercles on the base of prosternal process (latero–ventral view). The female is unknown.

Diagnosis. Agrilus duffelsorum sp. nov. is the only species of the group lacking prehumerus (Tab.1). The species is also very distinctive by peculiar sexual adaptation (see sexual dimorphism) and by shape of aedeagus (Fig. 5F).

Type material. Type locality: Malaysia, Sabah, 60 km W Sandakan, Sungai Darling, [05°53'00”N, 117°33'00”E] . Type specimens. Holotype ♂ (FWPC): “ Borneo, Sabah, Sungai Darling, 60 km W Sandakan, 26.xi.1989, M.J. & J.P. Duffels ”.

Distribution. Malaysia (Sabah).

Etymology. Patronymic; the species was named in honour of Duffels' family who collected the holotype.

Remarks. Known only from the holotype.