Atractocerinae Laporte, 1840

The Atractocerinae are unique among the Coleoptera in many respects, but notably in the extreme reduction of the elytra combined with the lack of transverse folds in the hind wings, which are almost completely exposed, lying over the abdomen. Based on the wing character alone, this subfamily was treated as a beetle suborder, Aplicalae, by King (1955); but Selander (1959) demonstrated that this wing type could be derived from that found in the lymexylid genus Melittomma . Likewise, Baehr (1976) in his detailed descriptive paper on the prothoracic morphology of “ Atractocerus sp.” commented on several structures (e.g., spinasternum, dorsal cervical sclerites, karepisternum, which “have been lost” in all other Coleoptera . Although this group appears to be derived from an ancestor well within the Polyphaga, the family Lymexylidae being part of or sister to the large superfamily Tenebrionoidea, the adult has certainly undergone major changes in body structure.

The ideas on relationships of atractocerines to other lymexylids have not really changed from those of Wheeler (1986), with the Palaearctic genus Lymexylon Fabricius as the sister group. It may be time, however, for a worldwide analysis to be performed based on adult and larval morphology and molecular data. This, however, is beyond the scope of the present study.

As noted in the Introduction, the subfamily now includes six extant genera: Arractocetus Kurosawa (1985), with ten species from Japan, Taiwan, Southeast Asia, the Philippines, India, Indonesia, New Guinea and the Moluccas; Atractocerus de Beauvois (1801), with eight species from Central and South America, the West Indies, tropical Africa, Madagascar, India, Sri Lanka, Sumatra and southern China; Fusicornis Philippi (1866), with a single species from Chile; Hymaloxylon Kurosawa (1985), with two species from India, Nepal and western China; Raractocetus Kurasawa (1985), with two species from India, the Philippines, Taiwan, Southeast Asia, Indonesia and Australia (introduced with Eucalyptus into New Zealand and Chile); and Urtea Paulus (2004) with one species from northern Greece. In addition, the following fossil Atractocerinae have been reported: Cretoatractocerus grimaldii WolfSchwenninger (2011), the earliest member of the group from the Lower Cretaceous (Upper Aptian) Crato Formation of Brazil, plus Vetatractocerus burmiticus Yamamoto,(2019), Raractocetus extinctus Yamamoto (2019) and R. fossilis Yamamoto (2019) from the mid-Cretaceous Burmese amber (earliest Cenomanian), R. balticus Yamamoto (2019) from mid-Eocene Baltic amber and Atractocerus sp. from Miocene Dominican amber (Yamamoto, 2019).