Rhembobius perscrutator (Thunberg, 1824)

Verheyde, Fons, Hoekstra, Paul, Libert, Pierre-Nicolas, Meijer, Hilco, Ketelaere, Augustijn De, Vandaudenard, Thibaud, Belgers, Dick & Brosens, Edwin, 1880, Two hundred and five ichneumonid wasps reported for the first time in Belgium and the Netherlands (Hymenoptera: Ichneumonidae), Belgian Journal of Entomology 122, pp. 1-142 : 51-52

Rhembobius perscrutator (Thunberg, 1824) (Fig. 21)

Rhembobius spp. are more robust and smaller cryptine wasps. Unique for the genus is the propodeum , with strong, coarse reticulation ( TOWNES, 1970a).

Rhembobius perscrutator is characterized by a black metasoma and black reddish legs. The dorsolateral carinae reach far (beyond the middle of the postpetiole) and are often distinctly striated. Striking are the extremely white tegulae (Fig. 21). There are also white bands on the apical tergites. The known hosts are hoverflies, which is exceptionally within Cryptinae

( HORSTMANN, 2000). Some of our specimens were caught with light traps. It has a long flying season, from April to October. First report for the Netherlands; confirmed in Belgium.

MATERIAL EXAMINED:

BELGIUM: • 1 ♀; Hoboken (AN); 51°10’41”N 4°21’02”E; 1/iv/2019; R. Hendrickx leg.; field observation; F. Verheyde det. (ObsID: 169445686) • 1 ♀; Houyet , Bois de Baronville (NA); 50°08’41”N 4°56’19”E; 26/x/2019; C. Steeman leg.; light trap; F. Verheyde det. (ObsID: 181692489) . • 1 ♀; Hove , Uilenbos (AN); 51°08’34”N 4°29’35”E; 5/ix/2020; Danny VG leg.; light trap; F. Verheyde det. (ObsID: 199607030) .

THE NETHERLANDS: • 1 ♀; Wageningen (GE); 51°57’59”N 5°40’24”E; 31/v/2019; D. Belgers leg.; field observation in skylight; F. Verheyde det. (ObsID: 173503282) . • 1 ♀; Wageningen (GE); 51°57’59”N 5°40’24”E; 14/vi/2019; D. Belgers leg.; field observation in skylight; F. Verheyde det. (ObsID: 174445536) . • 1 ♀; Wageningen (GE); 51°57’59”N 5°40’24”E; 18/vi/2019; D. Belgers leg.; field observation in skylight; F. Verheyde det. (ObsID: 174669086); Fig. 21 . • 1 ♀; Amsterdam, Osdorp (NH); 52°21’41”N 4°46’59”E; 16/x/2020; T. Kaizer leg.; field observation; F. Verheyde det. (ObsID: 201734645) . • 1 ♀; Utrecht (NH); 52°06’11”N 5°07’34”E; 31/x/2020; T. Kaizer leg.; field observation; F. Verheyde det. (ObsID: 202541473) .