Agenioideus sericeus (Vander Linden, 1827)

Verheyde, Fons, Jacobs, JEffrEY, Dekoninck, WOUTEr, Achterberg, Kees Van, Rond, JErOEn, Blanck, Tim De, Schoonvaere, KarEL, Nieuwenhuijsen, Hans, Ketelaere, Augustijn De, Minnebo, BarT & Ferrer-Suay, Mar, 2023, Remarks on Hymenoptera on urban green roofs in Belgium, Belgian Journal of Entomology 140, pp. 1-37 : 17

Agenioideus sericeus (Vander Linden, 1827)

BELGIUM: • 1 ♀; N51.160° E4.390°; viii/2021; J. Jacobs leg.; coll. FV ( RBINS); pitfall trap; H. Nieuwenhuijsen det.

Remarks:

This species belongs to the Subfamily Pompilinae , meaning it has a typical wing venation in the front wing, while any grooves on sternite 2 are missing. Agenioideus spp. have a narrow pterostigma (length of 2r-rs is smaller or equal to its width) and narrow antennal segments. Females of A. sericeus are more or less black with the propodeum smooth ( NIEUWENHUIJSEN, 2005).

Species in the genus are typically found on walls. It was once typified as rare in the Netherlands ( NIEUWENHUIJSEN, 2002), but in Belgium it has always been slightly more common (see also GROS &WAHIS, 2002). Last decades seem to suggest an increase of the species in both countries, with several new locations on citizen science portals. Presumably, the species (or some of its main preys) are thermophilic and are possibly influenced by climate change. It is not surprising then this species was found on green roofs in both countries (see Discussion and DRUKKER, DE BOER & FATOUROS, 2018).