Big-headed Mining Bees in Sidmouth Cemetery

In late April whilst looking for invertebrates in Sidmouth Cemetery I noticed a large swarm of male Andrena bees around the top of a hedge. When one eventually alighted for long enough for me to get a better view I was very pleased to see that they were the scarce bee, Andrena bucephala - Big-headed Mining Bee. I've seen one male previously down by the river in Sidford but never any females, so I returned a few days later to see if any females had emerged and they had, together with good numbers of the equally scarce kleptoparasitic bee, Nomada hirtipes - Long-horned Nomad Bee. Big-headed Mining Bee is its only host species.

Big-Headed Mining Bee - Andrena Bucephala

MALE

FEMALES

Long-horned Nomad Bee - Nomada hirtipes

MALES

FEMALES 

I found that they were nesting in an old rodent burrow on a steep bank but well hidden by vegetation. Big-headed Mining Bee is one of a few solitary bees which share a communal entrance but still make their own individual nests. I decided to revisit in a few days and see how they were progressing. I memorised the location, which was underneath the leaves of a large primrose plant, but as it happens I needn't have bothered because when I returned it was to find this somewhat over-zealous strimming.

I did eventually find the nest entrance again by watching for the bees flying in, but it was now very exposed. This didn't seem to deter the bees though and I saw many pollen laden females arriving at the nest as well as several of the klepoparasitic nomads.
 

Andrena Bucephala

Nomada hirtipes