This Gelis was found indoors on a window 13/9-2014, in my home near the Oslofjord. It is 3,6 mm long (excluding ovipositor, which is about as long as hindtibiae)
In Horstmann 1986: Die westpaläarktischen Arten der Gattung Gelis THUNBERG, 1827, mit macropteren oder brachypteren Weibchen
it ends up with G. brassicae (= G. cayennator).
In Schwarz 2009: Ostpaläarktische und orientalische Gelis-Arten (Hymenoptera, Ichneumonidae, Cryptinae) mit macropteren Weibchen
it ends up with G. cayennator:
Head and thorax black; wings hyaline. Ovipositor sheath 0.5-1.0 times as long as hind tibia; second tergite of gaster without distinct punctures. At least basal tergites with distinct sculpture. Femora III orange; 3. Fühlerglied (ohne Anellus) 2,4-2,6-mal so lang wie breit. Hind femur orange; third antennal segment (except anellus) 2.4-2.6 times as long as wide. (sorry I mixed up the english and the german key)
I would be very thankful if Schwarz (or someone else?) could confirm this one. Gelis cayennator is new to Norway, but I found pictures of a cayennator cf on Boldsystems from Sweden.