A soldier beetle larva in about 100 million years old amber adds chemical defence to the list of anti-predator strategies of immatures in the Kachin amber forest fauna

Abstract Soldier beetles have a relatively good fossil record, especially from Baltic amber and Kachin amber, Myanmar, summing up to about 200 formally described species of Cantharidae. Compared to 5500 extant species, this seems still not ample. Yet, the record is in fact largely restricted to adults. We report here a fossil soldier beetle larva from Kachin amber, identified as such based on densely spaced small setae on its body surface, given the larva a velvety appearance, and paired gland openings on most tergites. Further identification remains challenging due to an unusual character combination, a maxilla palp with three palpomeres (today only in Chauliognathinae) and a well developed galea (in all groups of Cantharidae besides Chauliognathinae). Despite the phylogenetic uncertainty, the larva expands the diversity of anti-predator strategies known of holometabolan larvae in the Kachin amber forest.