A new species of Hadraulacus Li, Shih & Ren, 2023 (Hymenoptera: Praeaulacidae) from mid-cretaceous Kachin amber

A new praeaulacid species, Hadraulacus liae sp. nov., is described and illustrated based on a female specimen from mid-Cretaceous Kachin amber. This new species reinforces the validity of key diagnostic characters used to define the genus Hadraulacus Li, Shih & Ren, 2023, such as the absence of the 2rs-m crossvein in the forewing. However, it also demonstrates that some traits previously considered diagnostic for the genus, like the tibial spur formula (1-1-2), represent mere interspecific variation and have limited taxonomic value. While the discovery of this species adds to the known diversity of Praeaulacidae in the mid-Cretaceous Kachin amber, it also highlights that the diversity of the subfamily Praeaulacinae within this biota remains significantly underestimated.