Dynastinae

Key to the species of Dynastinae from Lord Howe Island

1. Propygidial disc densely sculptured with transverse ridges..................................................... 2

- Propygidium smooth surfaced and evenly punctate, without stridulatory ridges.................................... 5

2(1) Propygidial disc with scattered unaligned and equal sized short transverse ridges, not forming a pair of stridulatory files; anterior margin of head rounded......................................................................... 3

- Propygidial disc with paired stridulatory files, formed by longitudinally aligned dense transverse ridges, decreasing in size from base to apex; anterior margin of head excavate either side of midline............... Heteronychus arator (Fabricius, 1775)

3(2) Mandibles bidentate; frontoclypeus with single median tubercle; 5–7 shallow elytral striae........................... 4

- Mandibles tridentate; frontoclypeus with either 2 tubercles or none; 9 deep elytral striae..................................................................................................... Metanastes vulgivagus (Olliff, 1889)

4(3) Base of pygidium setose; elytral punctures ocellate, with a fine ridge around each puncture... Pimelopus noctis (Olliff, 1889)

- Base of pygidium glabrous; elytral punctures simple, unridged.................. Pimelopus fischeri (Montrouzier, 1860)

5(1) Body flat; mentum expanded concealing bases of palpi; elytra densely punctured, relatively dull.......................................................................................... Cryptodus tasmannicus Westwood, 1841

- Body convex; mentum not laterally expanded; elytra not densely punctured, relatively shiny....................................................................................... Semanopterus kingstoni Reid & Tees, new species