Dear fellow entmologists, Can somebody help me with the determination of the Hymenoptera producing these stoppers or lids of their nest entrances? The photos are from Sweden about 100 km north of Stockholm at the coast. The grey stoppers (2 photos) are on bamboo sticks with 5-6 mm diameter hole and the green ones on wood with 4 mm diameter hole. You will find pictures at: http://arbetsplats.slu.se:4032/Shared%20Documents/StopperGrey.jpg http://arbetsplats.slu.se:4032/Shared%20Documents/StopperGrey2.jpg http://arbetsplats.slu.se:4032/Shared%20Documents/StopperGreen.jpg Many thanks in advance B?rge Pettersson