Crabro peltarius below is a digger wasp with an outstanding feature: it has a swollen front leg, or at least the males have. What the purpose of these swellings is, is virtually unknown, but it is believed they play some role in love making. All species of the genus Crabro have these swellings and they differ in each species. In Holland there are three species, the males of which can be told apart after some study, often even in the field. Crabro peltarius for instance has no or almost no yellow markings on its thorax. The other two species do. Females are extremely hard to tell apart from other female Digger Wasps. All species are fond of warm, sandy soils. They dig deep into the sand and provide the young with insects. In the case of this species usually Long-legged flies (family Dolichopodidae) are used.
Crabro peltarius is a common species in the Southern half of England only. It is on the wing from June to the end of September.