Earwig fan designing: Biomimetic and evolutionary biology applications.

Technologies to fold structures into compact shapes are required in multiple engineering applications. Earwigs (Dermaptera) fold their fanlike hind wings in a unique, highly sophisticated manner, granting them the most compact wing storage among all insects. The structural and material composition, in-flight reinforcement mechanisms, and bistable property of earwig wings have been previously studied. However, the geometrical rules required to reproduce their complex crease patterns have remained uncertain. Here we show the method to design an earwig-inspired fan by considering the flat foldability in the origami model, as informed by X-ray microcomputed tomography imaging. As our dedicated designing software shows, the earwig fan can be customized into artificial deployable structures of different sizes and configurations for use in architecture, aerospace, mechanical engineering, and daily use items. Moreover, the proposed method is able to reconstruct the wing-folding mechanism of an ancient earwig relative, the 280-million-year-old Protelytron permianum This allows us to propose evolutionary patterns that explain how extant earwigs acquired their wing-folding mechanism and to project hypothetical, extinct transitional forms. Our findings can be used as the basic design guidelines in biomimetic research for harnessing the excellent engineering properties of earwig wings, and demonstrate how a geometrical designing method can reveal morphofunctional evolutionary constraints and predict plausible biological disparity in deep time.

First record and new species of the genus Calambus Thomson (Coleoptera, Elateridae, Dendrometrinae) from Taiwan.

Calambus taiwanensis sp. n. is described from Taiwan, as the first record of the genus Calambus. This species is distinguished from its congeners by the male antennae extending beyond the apex of the pronotal hind angles by two apical antennomeres, antennomere III obconical and slightly longer than II, male aedeagus not expanded apically and without lateral subapical barbs, female genitalia with robust baculum and bursa copulatrix without sclerotized piece. The species is not included in any group suggested in past studies. A key to the five genera of the tribe Prosternini from Taiwan is provided.

The genus Nipponodrasterius Kishii (Coleoptera, Elateridae, Agrypninae), a junior synonym of the genus Gamepenthes Fleutiaux (Coleoptera, Elateridae, Elaterinae), with review of the Japanese Gamepenthes species.

The genus Nipponodrasterius Kishii, 1966 was established as a member of the subfamily Conoderinae Fleutiaux, 1919 (now tribe Oophorini Gistel, 1848; subfamily Agrypninae Candèze, 1857) based on N. alpicola. The genus was suggested to be unlikely to belong to Agrypninae because it lacks diagnostic features of the Agrypninae. However, there are no taxonomic treatments for the genus or species. Here, we review the status of the genus and species by examining the holotype of N. alpicola. Consequently, the genus was found to be a junior synonym of the genus Gamepenthes Fleutiaux, 1928 and N. alpicola was found to be a junior synonym of G. pictipennis (Lewis, 1894). We review all species of Gamepenthes in Japan and provide a key to species.

First record and two new species of the genus Limonius Eschscholtz (Coleoptera, Elateridae, Dendrometrinae) from Taiwan.

Limonius sapphirus sp. n. and L. onyx sp. n. are described from Taiwan, representing the first record of the genus Limonius in Taiwan. We provide an updated key to the genera of the subtribe Athouina in Taiwan and general morphological information of L. eximius Lewis, 1894 and L. ignicollis Lewis, 1894, which are endemic to Japan, for comparison with the two Taiwanese species. We believe that the two Taiwanese species and L. ignicollis are closely allied, sharing morphological characteristics of the lateral carina of prothorax, prosternal spine and aedeagus.

Taxonomy of the Leptogenys modiglianii species group from southeast Asia (Hymenoptera, Formicidae, Ponerinae).

Leptogenys brevilobasp. n., Leptogenys curvasp. n., Leptogenys itoisp. n., Leptogenys kanaoisp. n., Leptogenys malayanasp. n., and Leptogenys modiglianii Emery, 1900 are described from southeast Asia. The Leptogenys modiglianii species group is proposed on the basis of similarities among the six species. An identification key to species in this group from southeast Asia is provided.

The genus Alaolacon Candèze, a senior synonym of the genus Eumoeus Candèze (Coleoptera, Elateridae, Agrypninae).

Alaolacon Candèze, 1865 is found to be a senior synonym of Eumoeus Candèze, 1874, Luzonicus Fleutiaux, 1916 and Tharopsides Fleutiaux, 1918. Alaolacon is represented by Alaolacon bakeri (Fleutiaux, 1916), comb. n., Alaolacon candezei Fleutiaux, 1928, Alaolacon cyanipennis Candèze, 1865, Alaolacon fujiokaisp. n., Alaolacon griseus Candèze, 1874, Alaolacon megalopussp. n., Alaolacon murrayi (Candèze, 1874), comb. n., and Alaolacon philippinensisnom. n. This genus is redescribed based on the descriptions of three species, Alaolacon candezei, Alaolacon fujiokai, and Alaolacon megalopus as well as the examination of the holotypes of Alaolacon cyanipennis and Alaolacon murrayi comb. n. Males of the genus Alaolacon exhibit 12-segmented and biflabellate antennae, and the females exhibit 11-segmented and subpectinate antennae. A key to species is provided.

Rediscovery and redescription of Dilobitarsus pendleburyi (Coleoptera, Elateridae, Agrypninae) from Southeast Asia.

Dilobitarsus pendleburyi Fleutiaux, 1934 is recorded for the first time after its original description and is redescribed. This represents the first record from the Malay Peninsula, Malaysia and Sumatra, Indonesia. The systematic position of this species is discussed.

Taxonomic notes on three species of the genus Agonischius (Coleoptera, Elateridae, Elaterinae, Elaterini) with a new species from Taiwan.

Agonischius yokoyamai sp. nov. is described and represents the first record of Agonischius from Taiwan. This species resembles A. lateritius and A. insolitus, but is distinguished from the former by an orange body, yellowish-brown setae, longer antennae, and longer female sternite and tergite VIII, and from the latter by a wider body and differences in the male and female terminalia. Mouth-parts, abdominal terminalia and genitalia of this genus are described in detail and illustrated for the first time. These observations reveal that female sternite VIII and tergite VIII may be useful for species identification of Agonischius.