Xestonotus Förster, 1856

Awad, Jessica, Krogmann, Lars & Talamas, Elijah, 2023, Taxonomic history and review of the Förster genera of Platygastridae (Hymenoptera: Platygastroidea), European Journal of Taxonomy 875 (1), pp. 1-46 : 39-41

Genus Xestonotus Förster, 1856

(junior synonym of Leptacis Förster, 1856 )

Xestonotus Förster, 1856: 107 , 112. Type species Xestonotus andriciphilus Ashmead, 1887 by first subsequent inclusion. Junior synonym of Leptacis Förster, 1856 – Ghesquière 1948: 41–44. Preoccupied by Xestonotus Leconte, 1853 .

Xestonotidea Gahan, 1919: 524 . Replacement name for Xestonotus Förster, 1856 . Wrongly designated type species Xestonotidea foersteri Gahan, 1919 .

Axestonotus Kieffer, 1926: 625 . Replacement name for Xestonotus Förster, 1856 .

Eoxestonotus Debauche, 1947: 267 , 268, figs 11–15. Replacement name for Xestonotus Förster, 1856 . Wrongly designated type species Eoxestonotus pini Debauche, 1947 .

Remarks

The taxonomic history of Xestonotus is complex. Förster defined it by the nearly parallel notauli and smooth, blunt, relatively elongate mesoscutellum. Because he did not include any species, the type species was X. andriciphilus Ashmead, 1887 by first subsequent inclusion. However, Ashmead’s description and illustration were incongruous with Förster’s concept. Fouts (1924) transferred it to Platygaster , despite the fact that the type had already been lost. Ghesquière (1948) synonymized Xestonotus with Leptacis based on the drawing of X. andriciphilus from Ashmead (1893), an opinion seconded by Masner (1964). Adding to the confusion, the name Xestonotus was preoccupied by a beetle, Xestonotus Leconte, 1853 . Gahan (1919) proposed the replacement name Xestonotidea , but also named a new type species, Xestonotidea foersteri Gahan, 1919 . This type designation was determined to be invalid ( Muesebeck & Walkley 1956) because a replacement name for a genus always retains the original type species. Later suggestions for replacement names were Axestonotus Kieffer, 1926 and Eoxestonotus Debauche, 1947 , but priority makes these invalid. Debauche made the same mistake as Gahan, attempting to designate a new type species along with the replacement name.

Gahan and Debauche both intended to restore Förster’s concept of the genus, which was so obviously misinterpreted by Ashmead. However, once the type species was fixed by first subsequent inclusion, the genus was permanently linked to that concept. The only way to restore the concept was to erect a new genus with its own type species, hence Euxestonotus Fouts, 1925 . The type species is Platygaster error Fitch, 1865 , which is housed in the USNM. The NHMW has no material of special taxonomic significance to either Xestonotus or Euxestonotus .