02 April 2017

out and about with the bees and wasps, at last

Nice to get out a little this weekend, after a winter of indoor work on the bees and wasps. Lots of the usual early spring suspects are about e.g Bombylius discolor, Cicindela campestris and a few hoverflies.

Yesterday I cycled to Mumbles and hung about a Willow tree, camera in hand, took photos and tried to identify. Much to my surprise I did actually manage to identify some of them but it sure isn't easy, even after 5 years of intensive work. Because it's still so early in the year the vast majority of solitary bees seen are males, identified by the fact that they have 13 antennal segments compared to the female's 12. You can see them all in the better picture of Trimmer's Mining Bee below.

Firstly I found The Yellow Legged Mining Bee (Andrena flavipes), an old favourite as you can pretty much identify them in the field by the stripes of hairs on the abdomen and yellow haired back legs of the female. This one is a male and, as you can see below, is widely distributed on the Gower with 2 generations a year (bar chart) and nests in soft cliffs and other bare places, often in large numbers.
Secondly I found a male Cliff Mining Bee (Andrena thoracica), also widespread in much smaller numbers twice a year, and nesting in similar bare places to the bee above. It can easily be identified by the ginger thorax and black, very shiny abdomen in both the male and female. If you can see any white hairs it is not this species.
The third species I could identify is less widespread but also flies twice a year with a different appearance between spring and summer broods, a while ago treated as 2 different species. This is Trimmer's Mining Bee (Andrena trimmerana), identified in these photos by the red brown marks in the first 2 abdominal segments (red arrow) , the spine from the Gena below the eye (blue arrow) both best seen in the fuzzier photo, and the third antennal segment being half the length of the fourth, best seen in the clearer photo. In the summer generation of males the genal spine is absent, just to make life difficult.

Since 2012 I have been trying to record as many species of bee and wasp as I can on the Gower. I have not bothered much with Bumble Bees, nor Social Wasps and not at all with ants. I have recorded more than 200 species and if you want to look at all the maps they are here on my flickr website:

https://www.flickr.com/photos/iantew/albums/72157679972331290

A few maps are missing as the species are very difficult to sort out but hopefully I can add a few more maps very soon. There is much to be learned including, every time I think I've found something new I discover this is not the case, mostly. Keeps the excitement levels up! A few days after starting in 2012 I seem to have caught something new for Wales, Nomada guttulata, but it took me 5 years to get up the confidence to think it is correct. Confirmation of this will have to wait until The Bees Wasps and Ants recording scheme have trawled through my records unless someone knows better now! Numbers of insects shoot up and down alarmingly and distributions change a lot so contributions are always valuable and it takes a long time to get to know a site fully.

1 comment:

ian tew said...

Oops sorry. I meant to pay tribute to the excellent and very patient Barry Stewart who kindly talked me through the process of making maps from my data in Mapmate, cheers Barry.