This faded male bumblebee is, I believe, Barbut’s Cuckoo Bee. This species resembles its host, Garden Bumblebee (Bombus hortorum), but has an almost circular face, unlike the elongated face of Bombus hortorum. As a cuckoo bee, the female searches out a nest of its host bumblebee, entering the nest, usually killing the host queen, then laying its eggs in the nest. The cuckoo bees larvae are then fed and looked after by the host worker bees until they leave the nest in July - September.
The common wasps are back whenever we sit outside for a meal; but these two wasps are not the kind to bother you when you are eating.
The one on the left is a parasitoid wasp, rejoicing in the name Gasteruption jaculator. With its amazing long, white-tipped ovipositor it lays eggs into the nests of solitary bees, where its larvae will eat the bee larvae. According to the NBN atlas there’s not many records in Gloucestershire, so happy to snap it on my Goldenrod.
There’s a nice article here talking about the lifecycle (and name) of this pretty bizarre looking wasp https://www.gwct.org.uk/wildlife/species-of-the-month/2017/gasteruption-jaculator/.
The other wasp was fished out of the swimming pool, and with its smart black and yellow colour it looks like a potter wasp. These make their nests in hollow stems of plants like brambles, perhaps they might use a bee hotel as well. They hunt larvae from beetles and other insects, which they bring back to the nest for their own larvae. Species-wise I wondered about Gymnomerus laevipes (Box-header Potter Bee), but there are lots of similar-looking species, none of which seem especially well recorded and it’s hard to tell from the photos.
The Pellucid or Large Pied Hoverfly is one of the largest UK hoverflies, looking a little like a bumblebee and very fast-flying. With its white band round the body and black spots on the wings it is quite a striking insect. The adults feed on nectar from flowers, but lay their eggs in the underground nests of social wasps, like the Common or German Wasp. On hatching the larvae drop to the bottom of the wasps nest where they live on dead insects and unhatched wasp larvae, emerging as adults the following summer.
These nomad bees have been driving me mad the last few days as they are pretty small (+/- 1 cm) and hardly ever land for more than a few seconds. They just cruise around and around the elder trees in the wild corner of the garden. Today I got a break as one of them got trapped in a spider’s web enabling me to get a decent look. They really do look like mini wasps, patrolling around like wasps too; but close up you can see red mixed with the yellow stripes on the body. This one appears to be Flavous Nomad Bee (Nomada flava), but the identification between this species and Panzer’s Nomad Bee is pretty difficult. Nomad bees are kleptoparasitic cuckoo bees of mining bees; in this case usually Andrena scotica (Chocolate Mining Bee). Apparently the males search our the host bee’s nests, which they scent mark, helping the females to locate the nests for egg laying. The nomad bee’s larvae kill the host’s and any other nomad bee larvae present, so only one bee larva remains in the nest to feed of the stored pollen & nectar, the adult wasp emerging the next Spring.