Female Gorytes with a Cuckoo-spit bug Aphrophora alni, seemingly their only prey in our garden. I have yet to see them with any other species.

A few years ago Gorytes laticinctus was a rare wasp in Britain, found in a few sites mainly in south-east England. They nest mainly in loose sand, digging quite deep burrows in which they fill chambers with the adults of the cuckoo-spit bugs that the wasp larvae feed on.

They have been spreading across the country for a few years, but even so I was surprised to find one in our garden in June 2020 at the height of the pandemic. I was even more surprised a week or two later to find several nesting in a large container filled with and that I had built for sand-nesting bees and only filled in late Spring. How does a tiny insect find a small patch of sand miles from any other?

Going down. Gorytes taking prey to the nest chamber.

We have very little suitable nesting habitat for many miles around us so it is quite remarkable that one should have found a suitable site only 1m across, but four finding it at the same time seems very unlikely. I shall never be able to prove it but it seems possible that they arrived in a dumpy bag of sand I had had delivered after the first lockdown ended. Indeed I think it is likely that this may be one way they are moving around the country, especially in 2020 when bags of sand were left in one place for many weeks as building work stopped. Giving them plenty of time to start nesting before being moved to a location in another part of the country when work stated again.

Swarming males, somewhere in there is a female.
Mating Gorytes, only the bottom male is successful.

The colony has expanded rapidly in four seasons, both in 2022 and 2023 there was a peak of around 60 males at the colony with many more around the garden, the number of females nesting was at least the same and probably much higher. And I have made a second sand filled container for them. However this year their cleptoparasite Nysson trimaculatus appeared so the days of expansion may be limited.

Nysson watching a Gorytes at the entrancce to her burrow.
Female Nysson digging in to a Gorytes burrow.

In the early part of the season the males swarmed over the sand in a constant motion looking for newly emerged virgin females, any that appeared were pounced upon by up to 10 of the males. Any older females trying to nest had to run the gauntlet of the males as well on the way to their burrow when the returned with prey.