New flat wasps (Hymenoptera: Bethylidae) from the middle Cretaceous Kachin amber of Myanmar

Chrysidoid wasps are abundant and taxonomically diverse in middle Cretaceous Kachin amber, with numerous species described across nearly all chrysidoid families, including the speciose extant family Bethylidae. Despite ongoing taxonomic efforts, the tropical environment sampled in Burmese amber continues to yield a seemingly inexhaustible diversity of species within these lineages. Based on our examination of new wasp inclusions, we document the second Epyrinae taxon from Kachin amber as Chlorepyris mesocurvus n. sp., and present a micro-computed tomography reconstruction of its body. This species is particularly significant as it represents the first confidently assigned Cretaceous taxon within an extant genus, with implications for understanding potential morphological stasis and the origin of the subfamily. Additionally, we describe the second species of the Lancepyrinae genus Gwesped , named here Gwesped piastrii n. sp. This species can be readily distinguished from the previously known Gwesped species by its higher number of flagellomeres and distinctive forewing venation.