Belongs within: Elaterinae.
The Megapenthini are a tribe of click beetles diagnosed by having an arcuately carinate frons and the elytral apex truncate, scalloped, serrate and spinose rather than smooth and entire (Stibick 1979). The genus Megapenthes is widespread across most parts of the world other than southern South America (Calder 1996). Larvae of the western Palaearctic Megapenthes lugens live inside decaying beech and elm trees where they are predatory on weevil larvae.
Characters (from Stibick 1979): Head capsule oval, deflexed, mouthparts inferior, frontal carina complete, arcuate, bending down between antennae to meet or at least close towards labrum; antennae ll-segmented, serrate; prothorax more or less normally narrowed anteriorly, prosternal suture entire or excavated in front, double or single, surface of prosternal process more or less grooved between procoxae, procoxal cavities partly closed behind by a projection of the proepisternum, or anterior margin more or less angulate; scutellum shield-shaped, never cordate; mesocoxae open to both mesepimeron and mesepisternum; meso- and metasternum distinct, joined by a definite suture; elytral apex scalloped, truncate or at least serrate or spinose; tarsi simple; claws simple, without basal setae.
<==Megapenthini
|--Hayekpenthes parallelaris (Miwa 1927) [=Megapenthes parallelaris]PS07
|--Xanthopenthes granulipennis (Miwa 1929) [=Elater (Ectamenogonus) granulipennis]PS07
|--Pengamethes Fleutiaux 1928PS07
| `--P. koshunensis (Miwa 1929) [=Megapenthes koshunensis]PS07
|--AbelaterPS07
| |--A. babanus Kishii 1989PS07
| `--A. bousaianus Kishii 1991PS07
|--ProcraerusPS07
| |--P. sonami (Miwa 1929) [=Megapenthes sonami]PS07
| `--P. yagii Kishii 1994PS07
|--Wallaceus Schimmel 2004PS07
| |--W. novakorum Schimmel 2004PS07
| `--W. ronkayi Platia & Schimmel 2007PS07
`--Megapenthes Kiesenwetter 1858 [incl. Dolopiosomus Motschulsky 1859]J02
|--*M. lugens [=Elater lugens]C96
|--M. agrotusF89
|--M. andrewsi Waterhouse 1900JG19
|--M. apicatus Candèze 1865C96
|--M. automolus Candèze 1859C96
|--M. curtusF89
|--M. dolens Candèze 1859C96
|--M. lituratus Candèze 1887C96
|--M. luteipesF89
|--M. macdougalli Blair 1935C96
|--M. misellus Schwarz 1907C96
|--M. modestusF89
|--M. piceus Fleutiaux 1889F89
|--M. ruficollis Schwarz 1902C96
|--M. rufipes Candèze 1865C96
|--M. rufusF89
|--M. sturmi Germ. 1843 [incl. M. cribricollis Sturm 1826]FS90
|--M. tetricusF89
|--M. tinctipes (Candèze 1900) [=Elater tinctipes]C96
|--M. vicinus Fleutiaux 1889F89
`--M. vulneratus Schwarz 1907C96
*Type species of generic name indicated
References
[C96] Calder, A. A. 1996. Click beetles: genera of the Australian Elateridae (Coleoptera). CSIRO Australia: Collingwood.
[F89] Fleutiaux, E. 1889. Contributions a la faune Indo-Chinoise. Cicindelidae et Elateridae. 1er mémoire. Annales de la Société Entomologique de France, 6e série 9: 137–146.
[FS90] Fleutiaux, E., & A. Sallé. 1890. Liste des coléoptères de la Guadeloupe et descriptions d’espèces nouvelles. Annales de la Société Entomologique de France, 6e série 9: 351–484.
[JG19] James, D. J., P. T. Green, W. F. Humphreys & J. C. Z. Woinarski. 2019. Endemic species of Christmas Island, Indian Ocean. Records of the Western Australian Museum 34 (2): 55–114.
[J02] Johnson, P. J. 2002. Elateridae Leach 1815. In: Arnett, R. H., Jr, M. C. Thomas, P. E. Skelley & J. H. Frank (eds) American Beetles vol. 2. Polyphaga: Scarabaeoidea through Curculionoidea pp. 160–173. CRC Press.
[PS07] Platia, G., & R. Schimmel. 2007. Click beetles of Taiwan collected by the expeditions of the Hungarian Natural History Museum in the years 1995 to 2003 (Coleoptera: Elateridae). Annales Historico-Naturales Musei Nationalis Hungarici 99: 49–91.
Stibick, J. N. L. 1979. Classification of the Elateridae (Coleoptera). Relationships and classification of the subfamilies and tribes. Pacific Insects 20 (2–3): 145–186.