I have now found two other insects sharing the big nest aggregation I wrote about in my earlier post. One is a very small, mostly black, hunting wasp, Lindenius albilabris, which stocks its nest with even smaller flies and plant-bugs. I have previously found this in the Forest of Dean, nesting in the hard surface of a pathway at Crabtree Hill, constantly in use by walkers.
The other is the smallest bee I have yet found, Lasioglossum minutissimum, a member of the same group as the malachurum bees I previously wrote about. It was in the bottom of my net after a sweep in the low vegetation of the nesting area – a tiny black insect just 3.5 millimetres long which I otherwise would not have noticed.
Back home and under the microscope it showed by its branched hairs that it was a bee, by its 13 antennal segments that it was a male, and by its wing venation that it was a Lasioglossum. Apart from its very small size, its distinguishing feature is a shallow groove across the abdomen between the first and second segments.
Once I have found a bee for the first time, it often begins to appear in other places where it was unnoticed – in this case on the banks of the Monnow opposite the castle and at another site along the Wye at Dixton. Now I have learned to sweep the low vegetation and not to rely on spotting the bee first, this tiny insect appears to be fairly common around Monmouth. It is said to forage on a wide variety of flowers.