Sagrinae, also known as frog-legged beetles or kangaroo beetles, are a subfamily of the leaf beetles (Chrysomelidae).
Description Beetles in this subfamily feature distinctive enlarged hindlegs, giving them their common names. While both males and females display enlarged hindlegs, the males' legs are significantly larger, a form of sexual dimorphism. Male beetles additionally have a large spine on the ventral sides of their hindlegs, used for grasping and removing rival males during competitions for access to females.
Other identifying features include deep sutural stria, a prognathous head without a median sulcus and with cruciform grooves, a narrow pronotum, and commonly deeply indented eyes. They also have functional wings that aren't used often.
Most beetles of the subfamily display bright colors, and some can grow to be 1 to 2 inches in length.
Distribution and ecology This subfamily is found in Asia and has been observed in Malaysia, Java, Sumatra, Borneo, and the Philippines. It prefers dense tropical jungles for its habitat. There is fossil evidence that suggests these beetles lived in North America and Europe during the Eocene.
Reproduction There is not much known about reproduction and development in this subfamily. However, species in this subfamily often sport large cocoons in the post-larval stage which are commonly found on vining plants.
The cocoons represent a symbiotic relationship with a type of bacteria called Enterobacteriaceae because the bacteria play a role in the construction of the cocoons. This bacterium also functions as an intracellular symbiont with this subfamily of beetle, and lives in four large blind sacs at the larval foregut. The bacteria provide much needed nutrients throughout the beetle's life cycle.
Genera Tribe Carpophagini : Carpophagus MacLeay, 1827 Duboulaia Baly, 1871 Tribe Diaphanopsidini: Diaphanops Schönherr, 1845 Tribe Megamerini: Ametalla Hope, 1840 Atalasis Lacordaire, 1845 Coolgardica Blackburn, 1899 Mecynodera Hope, 1840 Megamerus MacLeay, 1827 Neodiaphanops Blackburn, 1899 Polyoptilus Germar, 1848 Pseudotoxotus Blackburn, 1889 †Palaeatalasis Legalov, 2021 – Green River Formation, Utah, Eocene (Ypresian) Tribe Sagrini: Sagra Fabricius, 1792 Incertae sedis: †Eosagra Haupt, 1950 – Geiseltal, Germany, Middle Eocene †Gallopsis Legalov, Kirejtshuk & Nel, 2019 – Menat Formation, France, Middle Paleocene †Pulchritudo Krell & Vitali, 2021 – Green River Formation, Colorado, Eocene (Ypresian)
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