Symmorphus allobrogusSymmorphus allobrogus is a species of potter wasps belonging to the subfamily Eumeninae.DistributionSpecies within this genus are present in most of Europe, in the eastern Palearctic realm, and in the Near East.DescriptionThese small solitary wasps can reach a length of about in females, of in males. They have a black thorax much longer than wide and a long and narrow abdomen with two yellow bands. The 4th abdominal tergite is usually completely black. The main segment of the antennae of males are completely black.BiologyThey nest in pre-existing cavities. Adult females prey on caterpillars and larvae of beetles to lay eggs in them. Adults fly from May to July.