Apsilops aquaticus (Thomson, 1874)

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 : 55

Apsilops aquaticus (Thomson, 1874)

Next to ‘soft’ characteristics such as colour, Apsilops spp. can be distinguished from related genera by the area superomedia (entirely delimited by carinae), the head and thorax which are densely hairy and the first abdominal segment and the propodeum that are coloured black.

A. aquaticus can be distinguished from the more common A. cinctorius by analysing the shape of the area superomedia, which is longer than wide in the latter species. The females of A. aquaticus have brownish antennae basally (red in A. cinctorius ), while the males have a white scutellum and black hind coxae (red in A. cinctorius ) ( SCHWARZ, 1989; SCHWARZ [2013], draft key). More striking than morphological features is the ecology. Apsilops spp. parasitize aquatic or semi-aquatic moths of the lepidopteran families Crambidae and Noctuidae ( YOSHIDA et al., 2011) . Therefore, they are often spotted on floating vegetation in ponds or ditches close to urban areas. First report for the Netherlands; unreported in Belgium.

MATERIAL EXAMINED:

THE NETHERLANDS: • 1 ♀; Ureterp , Terrein de Fûgelhelling (FR); 53°06’16”N 6°08’24”E; 20/ix/2015; H. Meijer leg.; coll. HM; field observation; H. Meijer det.