Quiet because of a much lower variety of birdsong, but there were some good insects and a couple of really nice songsters.
Butterflies were nice with a fresh Speckled Wood,
Pararge aegeria, and two others scrapping, over the brambles on the path in to the reserve by the houses. At the end of the walk there was a Green-veined White and a male Orange Tip along the concrete path.
The picture below shows a Bombus pascuorum doing something quite strange - it is investigating the remnants of an old Lamium album flower from which the corolla has already fallen off. There seems to be little to attract the bumblebee, and little advantage to the flower in attracting the bee. I wondered if this is a common observation?
Well, it turns out apparently that
Lamium is unusual in the family Lamiaceae in that the nectaries continue to secrete nectar for some time after the corolla falls off. This seems odd, but after all, why not if it perhaps more successfully facilitates pollination of the other flowers in the whorl, the structures are there anyway and perhaps it just shows common sense to leave them releasing for a day or two longer. This fits in with the often bizarre position of the nectaries in many other plants, by no means confined to the flowers themselves, for example perhaps being on leaves close-by.
The nectaries themselves in
Lamiaceae are often are a ring or torus of four individual structures surrounding the four ovary chambers. The fourth is however undeveloped and apparently vestigial in Basil, the three developed ones directed downwards towards the lower corolla lip. In other Lamiaceae there may be only one active lobe, the one with the thickest epidermis. The nectar-producing cells inside the nectaries are small and parenchymatous, with abundant inter-cellular spaces to release the nectar into. Starch acts as the carbohydrate store and builds up in them prior to anthesis, and then disappears as the flower develops and requires the sugary nectar. The stomata on the nectary surfaces are ultimately fed solely by the phloem vessels in some
Lamiaceae and are at least in some cases "anomocytic" (lacking in subsidiary cells), perhaps subsidiary cells being unnecessary where close control over opening and closing is unnecessary. However in
Lamium oddly enough there are more than two guard cells per nectary stoma!
Fuller details of the fascinating
Lamiaceae nectary structure and function can be found in the article in the South African Journal of Botany on Floral nectaries of Basil (
Ocimum basilicum): Morphology, anatomy and possible mode of secretion written by M.P. Mačukanović-Jocić, D.V. Rančić, and Z.P. Dajić Stevanović from the University of Belgrade.
This is a more conventional picture of a bee visit, with the anthers held over the back of the bee, releasing the pollen there. Much will be collected by the bees' legs perhaps and transferred to the pollen baskets. Other grains may end up on the stigma of the next flower to be visited.
This individual has quite worn wings so she is probably not fresh. She is quite a large insect judging by the size of the flower she is visiting, so she could be either a Queen from last winter or a large worker from the first generation this year. I am pretty sure she is the standard Carder,
B. pascuorum, as she has shaggy hair overall, paler hair on segment 1 of the abdomen than on segment 3, and a few black hairs do appear to be present on the back (and therefore maybe the side?) half way along the abdomen.
This is the same bee having moved on to another, more advanced whorl of flowers. Here, although most of the flowers in the whorl are over, there is at least one more to come! As the bee makes use of one of the flowers on the back of the whorl, you can see how the legs are being used to help hold the bee in position for nectaring, head held deep in the hood of the corolla. There might also be a tiny insect on one of the calyces to the front of the whorl.
Before the Bumblebee got on to that whorl it had been up to a bit of thievery, getting at the nectar by attacking the side of the corolla just above the ovaries:
