Ochosternus goodyeri Rosas, Chan & Reid, new species

(Figures 33–43)

Description (male only)

Length: male 15–17 mm (holotype 16 mm); greatest width of pronotum at hind angles 1.5× width of head; greatest width of elytra similar to pronotum at posterior angles; reddish-brown with darker base of head and pronotal disc, appendages reddish-brown, antennomeres with dark brown median streak.

Head. Dorsum with semi-erect setae, anteriorly directed on apical half, laterally directed on posterior half; almost evenly densely strongly punctured, interspaces ≤0.5× diameters, some confluent; interspaces shiny, feebly microsculptured; anterior margin of head in dorsal view convex, slightly projecting laterally beyond eyes, carinate; interocular space 2× eye widths in dorsal view; labrum strongly and densely punctured, with long setae, anterior edge convex; outer surface of mandibles strongly punctured and setose on more than proximal half, smooth and impunctate on distal 1/3, with weak depression at midpoint; male antennae about 0.6× length of body; scape and antennomeres 3–11 elongate, pedicel transverse; antennomeres 3–11 expanded, 3–10 elongate triangular, with concave apical margin and long apicolateral lobe in male, the lobe 0.5–0.7× antennomere length; relative lengths of antennomeres: male: 11> 7> 8=9> 5=6=10> 4> 3> 1> 2.

Thorax. Pronotal greatest length and breadth about equal, sides evenly expanded from anterior to base of posterior lobes, width at posterior angles 1.5× width at anterior angles; disc elevated at middle, with elongate depression either side; pronotal punctures smaller and sparser than on head, interspaces 1–1.5× diameters; interspaces shiny, feebly microsculptured; setae of disc semierect, mostly posteriorly directed; lateral pronotal carina weakly developed at anterior angles, but visible from above; posterior angles of pronotum about 25°; prosternum and hypomera strongly and closely punctured, with anteriorly directed depressed setae, except posterior half of hypomera glabrous and impunctate; mesoscutellum flat, shallowly and sparsely punctured, setose; elytral striae with distinct large punctures, intervals densely shallowly punctured; apices of elytra rounded; metaventrite densely and finely punctured and setose, punctures smaller than on hypomeron, and setae recumbent and posteriorly directed.

Abdomen. Ventrites with punctures and setae similar to metaventrite but punctures smaller; posterior margin of sternite 7 truncate.

Male genitalia. Tergite 8 about as broad as long, sides tapered to broadly rounded apex; sternite 8 medially membranous with three sclerotised areas, broad arcuate well-defined patch at base, and poorly defined apicolateral patches, apical margin shallowly concave; apical margin of tergite 9 shallowly emarginate, slightly bilobed; sternite 9 oval with basal aperture about 1/4 length of sternite; basal piece U-shaped but relatively short at midline, less than half overall length, sides angulate; median lobe with basal struts about 1/3 remaining length, which is gradually attenuated to curved apex; parameres elongate-triangular with almost straight sides and sharp pre-apical lateral barb.

Diagnosis. The following attributes distinguish O. goodyeri from other two species of Ochosternus on Lord Howe Island: anterior of frontoclypeus carinate (Fig. 35); male antennae about 0.6× body length (Fig. 34); antennomeres 3–10 pectinate (Fig. 36); anterior margin of labrum convex (Fig. 35); pronotum with elongate depression either side of middle, lateral margins entirely visible from above and evenly divergent from anterior to base of posterior lobes (Fig. 37); mesoscutellum flat, sparsely and shallowly punctured (Fig. 37); aedeagal basal piece short at midline (Fig. 43).

Material examined. Types. Holotype: m/ Mt Lidgbird Ld. Howe Is [in Olliff’s handwriting]/ foveicollis Lea Type Lord Howe [part printed, partly Lea’s handwriting]/ Ledgbirdia foveicollis Lea Lord Howe I Type [Lea’s handwriting]/ K39373 / Ochosternus goodyeri Rosas, Chan & Reid 2025 Holotype / [right antenna missing, also apex of penis and distal tarsomeres on all legs except left foreleg] (AMS); paratypes (2): m/ Lord Howe I. [printed]/ MAMU EN.66405 [printed]/ Ochosternus goodyeri Rosas, Chan & Reid 2025 paratype / [aedeagus extruded] (MMS); m/ MAMU EN.66410 [printed]/ Ochosternus goodyeri Rosas, Chan & Reid 2025 paratype / (MMS).

Etymology. Named in gratitude for Graham Goodyer, a retired NSW state agricultural entomologist who volunteered for many years at the Australian Museum to sort the Australian Elateridae collection to named genera.

Notes. The labels attached to the holotype show that Arthur Lea intended to describe this specimen as a new genus and species, but his name was never published. There is no additional material of this species in the Lea collection, South Australian Museum. All known specimens were collected before 1886 and lack detailed label data. The holotype was labelled ‘Mt Lidgbird’ by Olliff and was therefore almost certainly collected in 1885 (Olliff, 1889). The collector employed by the Australian Museum in the 1880s to visit the summit of Lidgbird (795m asl) is unlikely to have climbed above 400m asl and probably collected at a much lower elevation (Reid & Chan 2025). It is therefore probable that O. goodyeri is a lowland species that has not been collected since about 1885 and that it is extinct, like at least two other Coleoptera on Lord Howe Island (Anonymous 2002; Jensen et al. 2020).

Ochosternus goodyeri is similar in shape and general appearance to Megapenthes dolens Candèze, 1859, which is endemic to southwest Western Australia, but the latter has antennomere 3 short and unexpanded, and lacks pronotal depressions.