Pison atrum (Spinola)

Pulawski, Wojciech J., 2016, A New Synonymy in the Genus Pison Jurine, 1808 (Hymenoptera: Crabronidae), Proceedings of the California Academy of Sciences 63 (10), pp. 329-331 : 329-331

Pison atrum (Spinola)

Alyson ater Spinola, 1808:253 , sex not indicated. Lectotype: ♂, Italy: Liguria: Marassi near Genova (Torino), designated by de Beaumont, 1952:42. – As Pison ater (correctly: atrum ): Shuckard, 1838:75 (new combination).

Pison jurinei Spinola, 1808:256 , sex not indicated (as Jurini, incorrect original capitalization and termination). Lectotype: ♂, Italy: Liguria: no specific locality (Torino), designated by de Beaumont, 1952:42. Synonymized with Pison atrum by Shuckard, 1838:75, synonymy confirmed by de Beaumont, 1952:42 (as new synonym).

Tachybulus niger Latreille, 1809:75 , ♀. Syntypes: ♀, France: Brive and Italy: Genova (destroyed). Synonymized with Pison atrum by Shuckard, 1838:75.

Pison montanum Cameron, 1908:289 , ♂ (as montanus, incorrect original termination). Holotype by monotypy: ♂, Tanzania: Mount Kilimanjaro: Kibonoto (Naturhistoriska Riksmuseet Stockholm), examined. New synonym.

The African species Pison montanum was included by Turner (1916), Arnold (1924), and Leclercq (1965) in their keys to Afrotropical Pison , but apparently none of them examined the holotype. Of these authors, only Leclercq noticed the species close similarity to P. atrum , although he did not synonymize the two names.

Pison montanum , as traditionally interpreted, and also P. allonymum Schulz , another Afrotropical species, closely resemble P. atrum (the type species of the genus) in having the following combination of characters: presence of three submarginal cells, second recurrent vein joining second intersubmarginal cell or nearly so, punctures of upper frons coarse ( Fig. 1 ), propodeum without longitudinal carina separating side from dorsum and posterior surface, male sternum VIII broadly, deeply emarginate apically. Also, in most specimens the basal declivity of tergum I is covered with erect setae, and the hindcoxal dorsum has the inner carina produced into a conspicuous tooth basally, although the tooth is reduced in size or totally absent in many males.

Pison allonymum Schulz and P. montanum (as traditionally interpreted) differ by the position of the hindocelli: in P. allonymum , the ocellocular distance is larger than the hindocellar diameter; in P. montanum it is smaller than the midocellar diameter in the female and about equal to the midocellar diameter in the male. A hitherto unnoticed difference is the shape of the clypeal lamella of the female, which is obtusely, roundly angulate in P. allonymum and acutely angulate in P. montanum . Leclercq (1965) claimed that these species differ by the degree of punctation of gastral terga, but I cannot confirm his statement.

The holotype of Pison montanum has lost its head, but its remaining characters clearly indicate that it is either P. allonymum or P. montanum as traditionally interpreted. The absence of the head precludes recognition based on external characters, also because the position of the hindocelli was not mentioned in the original description. However, the setae of the gonocoxite of the holotype are as long as in the specimens determined as P. montanum in various collections and slightly longer than in P. allonymum , demonstrating that the species interpretation by Turner (1916), Arnold (1924), and Leclercq (1965) was correct.

In addition, Pison montanum is morphologically identical to P. atrum . These two names are therefore synonyms.

Pison atrum is known from southern Europe north to southern Germany, Austria, Czech Republic, Slovakia, Romania, southern Russia, Caucasus, and also from Algeria, Canary Islands, Morocco, Cyprus, Turkey and Iran. Pison montanum , described from Tanzania, was subsequently recorded from Ethiopia, South Africa, Zambia, and Zimbabwe. The combined geographic range extends from the Mediterranean Basin to South Africa.

Figures

FIGURE 1. Pison atrum (Spinola): upper frons of female.