Tachytes oviventris de Saussure, 1891

Pulawski, Wojciech J., 2019, A Review of the Wasp Genus Tachytes Panzer, 1806 of Madagascar (Hymenoptera: Crabronidae), Proceedings of the California Academy of Sciences 66 (7), pp. 117-135 : 134

Tachytes oviventris de Saussure

Tachytes oviventris de Saussure, 1891:260 , ♀. Holotype or syntypes: ♀, Madagascar: no specific locality (originally A. von Schulthess collection, now destroyed). – de Saussure, 1892:478 ( Madagascar, redescription); Dalla Torre, 1897:693 (in catalog of world Hymenoptera ); Arnold, 1945:109 (unrecognizable species); R. Bohart and Menke, 1976:266 (in checklist of world Sphecidae ); Pulawski, 2003:798 (in checklist of Malagasy Sphecidae ); Madl, 2014:987 (in catalog of Ampulicidae , Crabronidae , and Sphecidae of Madagascar, with synonymy and locality records).

Tachytes oviventris de Saussure, 1892:478 , ♀. Objective synonym of Tachytes oviventris de Saussure, 1891 .

DISCUSSION OF SPECIES IDENTITY.–The species was described rather concisely in 1891, in Latin only. In 1882, de Saussure repeated the Latin diagnosis almost verbatim, but provided a much more detailed description in French. Arnold (1945) commented about its unusual gaster coloration (he was not able to recognize the species). Indeed, the 1892 description mentions three characters unusual for a Tachytes : the gaster with bluish reflexes (abdomine coerulescente in Latin, abdomen … brilliant de reflets bleuâtres et pourprés in the French text), the postscutellum somewhat reddish mesally (postécusson un peu roux au milieu), and the recurrent veins attaining the 2 nd submarginal cell very close to each other (très près l’une de l’autre). Evidently, none of the Madagascan Tachytes show this unusual character combination, and it is unclear, what other genus might be involved. Unfortunately, the holotype seems to be lost. De Saussure (1892) said that the specimen belonged to A. von Schulthess, whose collection is now housed in the Eidgenössische Technische Hochschule in Zurich, Switzerland. Ms. Franziska Schmid of that institution wrote the following on 23 June 2009:

“Unfortunately I only found two types of Tachytes argyropis from Madagascar in the Schulthess collection. Because the Schulthess collection had passed a serious pest damage about 50 years ago, the individuals of Tachytes oviventris might have been lost”.

As Monsieur Bernard Landry kindly informed me (his e-mail of 13 September 2018), no specimen of T. oviventris can be found in de Saussure’s collection in the Muséum d’Histoire Naturelle de Genève, Switzerland, either. In conclusion, the species identity remains a mystery .