Ischnus agitator (Gravenhorst, 1829)

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 : 59-60

Ischnus agitator (Gravenhorst, 1829) (Fig. 26)

Ischnus spp. are hard to recognise by the basis of strong morphological characteristics (shape of the areolet, subpyramidal clypeus in profile), but luckily most species have a remarkable habitus (see also TOWNES, 1970a; SCHWARZ [2013], draft key).

I. agitator is the only species in the genus with a red thorax and propodeum. The head is black, just like the apical tergites of the metasoma. This makes it a colourful species with quite some contrast (Fig. 26). Additionally, the metapleuron is distinctly punctured. Although probably uncommon, the species could be expected to be present, with all surrounding countries having distributional details (see FAUNA EUROPAEA). One of the known hosts is the common sawfly Hemichroa australis (Serville, 1823) (Symphyta: Tenthredinidae ) ( RUDOW, 1918).

First report for Belgium and the Netherlands.

MATERIAL EXAMINED:

BELGIUM: • 1 ♀; Knokke , Het Zwin - Duinengordel (WVL); 51°21’56”N 3°21’16”E; 19/vii/2017; P. Vanhauwere leg. [UGent]; coll. KBIN/RBINS (ENDURE-project, 160_ZWN_10_N); field observation; F. Verheyde det.; Fig. 26 . • 1 ♀; Anderlecht (BR); 50°48’27”N 4°17’07”E; 6/ix/2020; L. Boon leg.; field observation; F. Verheyde det. (ObsID: 199689520) .

THE NETHERLANDS: • 1 ♀; Otterlo , Veluwe (GE); 52°02’40”N 5°48’29”E; 21/vi/2019; R. van Ekeris leg.; field observation; F. Verheyde det. (ObsID: 174871966) . • 1 ♀; Drachten (FR); 53°05’50”N 6°04’23”E; 24/iii/2020; R. Offereins leg.; field observation; F. Verheyde & M. Schwarz det. (ObsID: 187140967) .