After a run of autumnal days the wind has now moved back into the south-west, where it belongs, and today the temperature shot up by several degrees. This brought out an interesting range of invertebrates, several of which I’d never recorded in the garden before. If I’d managed better images I’d probably have posted Beris chalybata, the murky-legged black legionnaire soldierfly, simply because of his common name, but he was lurking under the trees in the darkest section of the wild garden, where even record shots were a challenge. The same, sadly, was true of a little chalcid wasp which I think was Haltichella rufipes – though it’s unlikely that I’ll be allowed to record it as such because the chalcids are notoriously tricky to identify from photos.
As I mentioned when I posted Nomada lathburiana a few days ago, the same is often said of the tri-coloured nomads, but once again I’m confident on this one. I ran all of my photos of her through the Obsidentify app, and every one was named with 100% certainty as Nomada zonata – but then, because you can’t be too careful, I also posted a few images on Twitter and asked Steven Falk (The Man Who Knows) for confirmation, which he kindly gave a short while later.
Nomada zonata is a relative newcomer to the UK, but appears to be spreading fast, and colonising successfully as it travels. It was known only as a mainland European species until 2011, when it was discovered on Jersey. In 2016 it was found on the British mainland in Kent and Essex, and in 2019 it turned up in Norfolk and Northamptonshire. In replying to my query, Steven Falk said that he’d first found it in Warwickshire in 2021, and wondered how many Worcestershire records there might be – which is a question I’ll be raising with fellow invertebrate recorders and with the local Wildlife Trust. It surely can’t be the first specimen to have turned up in the county (though obviously I’d love to find that it was), but it’s unlikely to be common here as yet.
Nomada zonata is also known as the variable nomad bee, because its markings, especially in females, are (you guessed it) highly variable. Unusually though, the underside of the female’s abdomen is bright red, so if you find a nomad you think might be N. zonata, coax her into rolling over to have her tummy tickled and you’ll get your confirmation. Males are largely black and yellow, though they can have some red on the abdomen, and look very similar to males of the much commoner species Nomada marshamella.
The host of this cleptoparasite is Andrena dorsata, the short-fringed mining bee. Both host and parasite are bivoltine – that is, they produce two broods per season – the first generation peaking in May, and the second in July.