Pison esakii Yasumatsu, 1937

Pulawski, Wojciech J., 2018, A Revision of the Wasp Genus Pison Jurine, 1808 of Australia and New Zealand, New Guinea, and the Pacific Islands (Hymenoptera: Crabronidae), Proceedings of the California Academy of Sciences 65, pp. 1-584 : 532

Pison esakii Yasumatsu

Figures 1288-1292.

As Pison sp. : Fullaway, 1913:283 ( Guam) and Swezey, 1942:185 ( Guam), corrected to Pison esakii by Krombein, 1949b:401.

Pison esakii Yasumatsu, 1937b:129 , ♀. Holotype: ♀, Mariana Islands: Island of Rota (ELKU), examined. – Yasumatsu, 1939:83 (in key to Pison of eastern Asia, in checklist of Pison of Japanese Empire), Krombein, 1949b:384 (in key to Sphecidae of Micronesia), 401 (diagnostic characters; Mariana Islands); Yasumatsu, 1953:134 (in list of Pison of Pacific islands), 139 (bibliographic references; Mariana Islands); Tsuneki, 1968b:21 ( Mariana Islands, description of ♂); R. Bohart and Menke, 1976:335 (in checklist of world Sphecidae ).

RECOGNITION.– Pison esakii and P. nigellum are the only Pacific Islands species with black setae on the upper frons, gena (Fig. 1290), thorax, and propodeum (Fig. 1291). Subsidiary recognition features are: punctures 2-3 diameters apart on frons, several diameters apart on scutal disk and propodeal dorsum, setae of lower gena sinuous, about as long as 1.5 × midocellar width and appressed on tergum I, ocellocular distance about 0.3 × hindocellar diameter, wing membrane black, and gastral terga without silvery, apical fasciae. Unlike P. nigellum , the propodeum of P. esakii has a longitudinal carina separating the dorsum from the side (carina absent in P. nigellum ), a well-defined median carina within a well-defined sulcus (Fig. 1291) whereas the carina and sulcus are inconspicuous in P. nigellum , and the propodeal posterior surface with conspicuous, transverse ridges (unridged in dorsal half in P. nigellum ).

DESCRIPTION.– Frons dull, microsculptured, with well-defined punctures that average 2-3 to several diameters apart (Fig. 1289). Labrum minimally shallowly emarginate. Anteromedian pronotal pit transversely elongate, about as long as 1.5 × midocellar diameter. Scutum not foveate along flange, without short longitudinal ridges adjacent to posterior margin; scutal punctures fine but well defined, several diameters apart (about one diameter apart near to foremargin). Tegula not enlarged. Mesopleural punctures well defined, averaging several diameters apart at center. Postspiracular carina present, about 1.5 × as long as midocellar diameter; integument narrowly depressed between postspiracular carina and episternal sulcus. Metapleural sulcus costulate between dorsal and ventral metapleural pits. Propodeum with irregular longitudinal carina separating side from dorsum and posterior surface and extending posterad from spiracle area but not reaching gastral socket; dorsum unridged, minutely punctate (punctures several diameters apart except about one diameter apart laterally), with well-defined median carina in well-defined sulcus; side finely punctate, punctures about one diameter apart, interspaces merging into fine ridges well visible from several angles; posterior surface conspicuously, transversely ridged, minutely punctate between ridges. Posteroventral forefemoral surface finely punctate, punctures many diameters apart. Hindcoxal dorsum with outer margin sharply carinate in posterior half. Horizontal part of tergum I, terga II-IV, and sternum II with microscopic punctures that are many diameters apart, interspaces unsculptured, shiny.

Setae black on the head (Fig. 1290), thorax, and propodeum (Fig. 1291) except silvery on lower frons laterally and on clypeus laterally, erect on upper frons, postocellar area, scutum (here about as long as one midocellar diameter), not concealing integument on clypeus; setae of lower gena sinuous, about as long as 1.5 × midocellar diameter. Apical depressions of terga without setal, specific locality (2 ♀, 1 ♂, BISH) . Island of Rota: Tatâcho-Sonson (1 ♀, ELKU, holotype of Pison esakii ), no specific locality (1 ♀, CAS) .