Xiphydriidae are a family of wood wasps that includes around 150 species. They are located all over the world including North and South America, Australia, Europe, and others. Xiphydriidae larvae are wood borers in dead trees or branches of a range of trees. They are characterized as having long and skinny necks with dome-shaped heads. The oldest fossils of the group are from the mid Cretaceous. Genera These 29 genera belong to the family Xiphydriidae: Alloxiphia Wei, 2002 Austrocyrta Riek, 1955 Austroxiphyda Jennings, Macdonald, Schiff & Parslow, 2021 Brachyxiphus Philippi, 1871 Calexiphyda Smith, 2008 Carinoxiphia Wei, 1999 Derecyrta Smith, 1860 Eoxiphia Maa, 1949 Euxiphydria Semenov-Tian-Shanskii & Gussakovskii, 1935 Genaxiphia Maa, 1949 Gryponeura Benson, 1954 Heteroxiphia Saini & Singh, 1987 Hyperxiphia Maa, 1949 Indoxiphia Maa, 1949 Lataxiphyda Smith, 2008 Lissoxiphyda Smith, 2008 Megaxiphia Wei, 1999 Moaxiphia Maa, 1949 Obesaxiphyda Smith, 2008 Platyxiphydria Takeuchi, 1938 Rhysacephala Benson, 1954 Steirocephala Benson, 1954 Trixiphidia Wei, 1999 Xiphidiaphora Benson, 1954 Xiphydria Latreille, 1802 Xiphydriola Semenov-Tian-Shanskii, 1921 Yangixiphia Wei, 2002 † Paraxiphydria Gao et al, 2022 Burmese amber, Myanmar Cretaceous Albian-Cenomanian Anatomy and morphology Head Most of the species of Xiphydriidae have antennae that are filiform. The antennal segments vary in number ranging from 14 to 22. The maxillary and labial palpi shape and length varies by species. They have an occipital carina which is a ridge in the back of the head. The head is somewhat spherical and is shiny. Thorax The pronotum is medially constricted in Xiphydriidae. The defined axillae completely separates the scutum laterally from the mesoscutellum. Parts of the thorax for Xiphydriidae are generally smooth and shiny. Abdomen The segment of the abdomen called the gaster can have an orange, red, or yellow coloring pattern. A study by David R. Smith broke the Xiphydriidae into different groups by their abdomen. The groups were as follows: Xiphydriidae that have a maxillary palpus segmented into 7. Xiphydriidae that have short maxillary palpi and contain female fore claws with inner tooth. Xiphydriidae that have short maxillary palpi and also contain claws of both sexes with inner tooth. Life cycle and development Larva The Xiphydriidae larvae phytophagous, meaning bore into dead or weak trees and plants. When they are buried in these trees, they rely on symbiotic fungi for food in the tunnels that they made. The larva either do not have legs or they have vestigial legs. During the larval stage, the head of Xiphydriidae