Andrena bucephala (Hymenoptera: Andrenidae) new to Suffolk.

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M. Ferris

Andrena bucephala (Hymenoptera: Andrenidae) new to Suffolk Late afternoon on the 13th May 2020, in the small village of Denston, West Suffolk, I was in the middle of working on a small project in my garden when I happened to notice an Andrena species had alighted on a piece of wood next to where I was working. On closer inspection it was a female with a full pollen load and looked quite different from the Andrena nigroaenea and A. scotica that had active nests in my garden. It seemed to be resting (the weather had suddenly turned cool and overcast) so I quickly grabbed my camera and took shots from various angles. When the weather improved it went on its way.

Upon examining the photos at the end of May, the first feature that struck me was the yellow/amber wash to the wings and along the costa vein. Also noticeable were the largely unmarked tergites and slim looking abdomen (looking particularly tapered where it met the thorax) giving it a pinched-in appearance. I had recently purchased the excellent, updated "Field Guide to the Bees of Britain and Ireland" by Steven Falk and used this to help try and determine the identification. The only Andrena that it seemed to match was Andrena bucephala, a species not previously recorded from the county. I then posted my photos on the "UK Bees, Wasps and Ants" Facebook webpage, to see if anyone agreed that it could be Andrena bucephala. Stephen Boulton (admin for the page and experienced melittologist) commented that he thought it looked good for Andrena bucephala. I then decided to contact Steven Falk with my photos and he was happy that it was, indeed, Andrena bucephala. He then mentioned what a great discovery it was, and that they were having a good season in Warwickshire and Oxfordshire, where he’d been undertaking bee surveys.

Trans. Suffolk Nat. Soc. 56 (2020)

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Suffolk Natural History, Vol. 56

Not knowing that it could be a first for Suffolk, I didn't take a specimen and, despite searching, came to the conclusion that their flight period had possibly come to an end by the time its true identity was determined. This record constitutes the first recorded sighting in Suffolk and only the second for East Anglia. Nick Owens informed me that there is a population of Andrena bucephala in Cambridge Botanic Garden in their ‘chalk bank’. They share the nest entrances (3 or 4 close together) with Andrena scotica.

The species is widely distributed in southern England and south Wales but is generally rare and very local. It is possible that there has been a slow range expansion from the south or west into East Anglia, mirroring the eastward expansion of Andrena cineraria. The main forage plants are Hawthorn (Crataegus spp.), Field Maple (Acer campestre) and Sycamore (Acer pseudoplatanus) and my garden is surrounded by most of these, particularly Acer and Crataegus. Favoured habitats include scrubby calcareous grassland and old limestone quarries and cuttings with south facing slopes.

It has also been recorded from open woodland, parkland and private gardens.

Unlike most Andrena species they nest communally with many females sharing a nest entrance and is assumed that each female has her own nest burrow. Nests are commonly excavated in rough grassland, on the slopes of cuttings, and quarry sides, but have also been seen nesting at the base of old tree stumps and around graves in cemeteries.

References Falk, S. J. & Lewington, R. (2015). Field Guide to the Bees of Great Britain and Ireland.

British Wildlife Publishing.

Mark Ferris 6 Top Green, Denston, Newmarket, Suffolk, CB8 8PW

Trans. Suffolk Nat. Soc. 56 (2020)