Therion circumflexum

This species is widespread in large parts of the Palearctic realm (Europe, Asia, North Africa) and also occurs in the Nearctic realm (North America).[2]

Therion circumflexum can reach a body length of approximately 14–25 millimetres (0.55–0.98 in). The head and thorax of these relatively large parasitic wasps are predominantly black. The scutellum is yellow. The abdomen is predominantly orange. Usually the rear end and the top of the third tergites are black. The female has a short spike. The legs are yellow-orange. The posterior femur and posterior tibia have a dark brown apical end. The wings are orange-hyaline. In the clypeus the median apicali tooth is missing and the hind tarsal claws are evenly curved.[3]

The adult parasitoid wasps of this species fly from mid-June to September. They parasitize various butterfly species. These butterflies include the small engrailed (Ectropis crepuscularia), the privet hawk moth (Sphinx ligustri), the pine hawk-moth (Sphinx pinastri), the pebble prominent (Notodonta ziczac) and a number of moths (Noctuidae). The female wasp lays its eggs in the caterpillars. The hatched larvae feed on the caterpillar and pupates later in a thin web.[4]