Rise of the Armed Nomads

Last Sunday morning I was walking in the Buckinghamshire Chilterns. I was feeling a bit tired and unenthusiastic, and for once was not really thinking about recording insects. But it’s impossible to completely turn off the entomological instincts, and a fairly large cuckoo bee (or nomad bee, genus Nomada) caught my eye. It was flying among the vegetation at the top of a bank on BBOWT‘s Grangelands nature reserve.

Armed Nomad bee female at Grangelands – very fuzzy photo!

I took a quick snap but wasn’t very careful about it, and the bee soon vanished into the undergrowth. But it had looked somehow different, and as I walked home it dawned on me that it just might have been something special. By the time I got home I was keen to see the photo, but I’d done a really poor job – blurry and distant. Even so, what few details I could make out were consistent with it being something potentially very special: was there a chance it could be the Armed Nomad Bee, Nomada armata.

That, however,  is a Red Data Book 1 species, and listed as being of ‘Principal Importance’ in the NERC Act. And as far as I knew it hadn’t been seen anywhere outside Salisbury Plain for about 50 years. So a grotty blurred photo wasn’t really going to cut it.

Nomada bees are ‘cleptoparasitic’ bees that take over the nests of other bees. The host for the Armed Nomad is Andrena hattorfiana, the Large Scabious Mining Bee, itself a rare species but one that has been spreading, and was first found in Buckinghamshire in 2007, by Aaron Woods, near Beaconsfield. Following that it has been seen at a few other sites, including at Grangelands, where Ryan Clark discovered it a few years ago. So it was at least conceivable that the Armed Nomad had started to follow the expanding range of its host.

Armed Nomad bee male at Grangelands - photo 2 by Martin Harvey
Armed Nomad bee male at Grangelands showing its distinctive broad front femora

But I needed better supporting evidence! And it was getting late in the afternoon by now. So back up the hill I went. Needless to say there was no sign of the female Nomada in the original location, so I set off in search of Field Scabious flowers, which are the flower required by Andrena hattorfiana, and also visited by Nomada armata. After about an hour and a half of searching, and on the opposite side of the reserve from the morning’s sighting, I saw a bee on a Field Scabious flowers.

Armed Nomad bee male at Geangelands - photo by Martin Harvey
Armed Nomad bee male at Grangelands – note the bright orange antennae

Nervous with excitement I nearly fumbled the net, but managed to catch what turned out to be a male Armed Nomad. Some slightly better photos ensued, and as soon as I got home I sent these to Stuart Roberts of BWARS, who very promptly confirmed the identification – thanks Stuart.

As far as I know this is the first time the Armed Nomad has been seen in Buckinghamshire, and the first time for about 50 years that it had been recorded away from Salisbury Plain – or so I thought …

Armed Nomad bee, female, at Dry Sandford Pit - photo by Peter Creed
Armed Nomad bee, female, at Dry Sandford Pit (photo by Peter Creed)

I reported the find to BBOWT, who passed the message on to Peter Creed, author of A guide to finding bees in Berkshire, Buckinghamshire and Oxfordshire. To my amazement Peter got in touch to say that he had also found Nomada armata the same weekend as I did, but at another BBOWT reserve, Dry Sandford Pit in Oxfordshire (vice-county Berkshire). This is a site where it had been recorded before, back in the 1970s. The known range of Nomada armata had suddenly expanded considerably!

Large Scabious Mining Bee female at Grangelands - photo by Martin Harvey
Large Scabious Mining Bee female at Grangelands

Another trip to Grangelands a couple of days later produced good sightings of the host bee Andrena hattorfiana, and one further male Nomada armata. So it looks like it has established itself on the reserve.

It’s always encouraging to see rare species making a recovery, and while it is early days for this one the hope is that both host bee and cuckoo will continue to strengthen their populations and distribution. And BBOWT’s reserves are clearly playing an important role in allowing them to do so. It’s intriguing to think what journeys the Nomada must have made to get from Salisbury Plain to the Buckinghamshire Chilterns.

Armed Nomad bee male at Grangelands - photo 4 by Martin Harvey
Armed Nomad bee male at Grangelands

For more information on the Armed Nomad see the factsheet from Buglife (pdf). Steven Falk has more photos of Andrena hattorfiana and Nomada armata.

 

3 Replies to “Rise of the Armed Nomads”

    1. Yes – it seems likely that there must be other ‘stepping-stone’ sites in between Salisbury Plain and these two BBOWT reserves.

  1. AH Hamm found it in the Dry Sandford area in the early 20th Century and Chris O’Toole had one in a malaise trap in his Oxford garden in the 1980’s

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