Tuesday 15 May 2018
I visited a large, SW-facing organic pasture near Hendre, NW Monmouthshire, ungrazed since the previous year. The recent sunny weather on this day produced a really interesting list of bees. This includes six different nomad bees, one of which is described in Falk and Lewington’s Field Guide as ‘a very scarce species’: Short-spined Nomad Bee (Nomada guttulata). Nomads are cuckoo-bees, or klepto-parasites, which lay their eggs in the nests of others, usually mining bees.
The small, red and black cuckoo-bee was flying with its host, Red-girdled Mining Bee (Andrena labiata, also small, red and black) in a corner of the meadow, over a patch of Germander Speedwell, the mining bee’s favoured flower. Only when I got the cuckoo bee home under the microscope and followed it through the Field Guide key did I realize what I had found. My identification was confirmed when I sent it to a BWARS expert.
While the mining bee is ‘rare and mostly coastal’ in Wales (though it is present in Drybridge Park, Monmouth), the cuckoo bee is much rarer than its host.
The other nomad bees were (using Steven Falk’s English names): Marsham’s, Fork-jawed, Gooden’s, Painted and Flavous. Three other cuckoo-bees (small, red and black again) were Blood-bees (Sphecodes): Box-headed, Geoffroy’s and Red-tailed.
Besides these I found nine other non-parasitic bees, including several males of Large Meadow Mining Bee (Andrena labialis), which I first found at this site. It is the only bee in this story not small, red and black.
The number and variety of cuckoo-bees flying about in the Spring makes one wonder how their hosts manage to replace themselves at all.