A beetle-like minute litter bug trapped in 99 million-year-old Kachin amber (Hemiptera, Dipsocoromorpha, Schizopteridae)

Abstract

Minute litter bugs (Dipsocoromorpha) constitute one of the most ancient and specialized lineages of Heteroptera. This infraorder displays an array of deviant body structures, such as dramatically varying tarsal formula, asymmetrical male abdominal terminal segments, and beetle-like appearance with elytriform tegmina. Most these unusual morphological traits have been reported in early dipsocoromorphans, except the stunning coleopteroid wings. Herein, a new minute litter bug, Qiaoia menghaoae Chen and Zhuo, gen. et sp. nov. is described from middle Cretaceous Kachin amber, northern Myanmar, representing the first beetle-like dipsocoromorphan in the Mesozoic. The new genus and species is characterized by three pairs of extremely strong spine-like trichobothria on vertex and pronotum, thoracic legs densely covered with tiny setae and long spines, hemelytra generally dark-stained and with a narrow bright transverse stripe in middle. Our new find further confirms that the grotesque morphological characteristics displayed in modern minute litter bugs have evolved and likely prevalent in their Cretaceous ancestors. Additionally, morphological analyses suggest some Mesozoic dipsocoromorphans including Qiaoia menghaoae Chen and Zhuo, gen. et sp. nov. probably lived in relatively open areas like arboreal habitats and were more mobile and active than their recent descendants, which are commonly with cryptic life style.