Ischyrosonychini Chapuis, 1875

Sekerka, Lukáš, 2016, Taxonomic and nomenclatural changes in Cassidinae (Coleoptera: Chrysomelidae), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 275-344 : 308

Tribe Ischyrosonychini Chapuis, 1875

Remarks. This tribe is assemblage of three groups previously considered as distinct tribes: Asterizini, Ischyrosonychini and Physonotini . BOROWIEC (1995) suggested that all three should be united because of lack of synapomorphies based on adult characters and used the name Ischyrosonychini as the valid name. BOROWIEC (1999a) also considered the three taxa synonymous, however, used Physonotini as the valid name because Ischyrosonychini were based on a genus that was a junior synonym of Eurypedus Gistel, 1834 . However, Physonotini Spaeth, 1942 was proposed after 1930 without description or bibliographic reference to such description thus being unavailable ( ICZN 1999: Article 13.1) and therefore the name was recently changed again to Ischyrosonychini ( BOUCHARD et al. 2011).

Ischyrosonychini are superficially similar to Cassidini and are quite difficult to define and separate from the latter tribe based solely on adult morphology. ŚWIĘTOJAŃSKA & WINDSOR (2008) discussed their position based on larval morphology and concluded that Ischyrosonychini possessed features characteristic for primitive (generalized) tribes of Cassidinae s. str. while Cassidini were considered as derived. The head of adult specimens of Ischyrosonychini is more similar to Goniocheniini or Omocerini as the head is distinctly transverse with small eyes situated in front of the mouthparts, while Cassidini have circular head, mostly with large eyes. In addition all Ischyrosonychini have simple and quite long tarsal claws and the ultimate tarsomere is somewhat longer than in most Cassidini and as a result they are capable of faster movement than most of Cassidini . Also the larvae of Ischyrosonychini move more rapidly than those of Cassidini (L. Sekerka, unpubl. observation).

Two genera, Orexita Spaeth, 1911 and Aidoia Spaeth, 1952 , currently classified in Cassidini , have a strongly transverse head with small eyes and similar structure of tarsi as Ischyrosonychini and I transfer them to the latter tribe. The affinity of the two genera to Ischyrosonychini as well as affinities of the genera within the tribe should be verified by molecular data. The genera of Ischyrosonychini can be recognized using the key below.