Cherry pollinators fest!

It was a warm, sunny afternoon and the cherry was at full bloom (three weeks earlier than last year), attracting a menagerie of bees, butterflies, queen wasps and flies. I did saw a honeybee, but I think even without this species, the cherry would be fully pollinated given the number and diversity of insects on it.

 Several bees were firsts for the year, including Bombus lapidarius, B. pascuorum and Melecta albifrons. I saw the first male red mining bee yesterday but they seemed to be everywhere today.

Bombus lapidarius queen 

Anthophora plumipes female

Queen wasp grooming

Possibly a dronefly

Male Osmia bicornis

and a Peacock also settled repeatedly on the blossom to feed

A small shining metallic wasp fell on the small pond and was rescued.

The first water beetle in the Victorian bath that makes our mini pond, awaiting ID.

Melecta albifrons, a cuckoo bee that parasitises A. plumipes, feeding on Muscari

 Melecta albifrons,  resting on a daffodil

And finally, a shot of a Red Mason Bee patrolling the Muscari.

A beesy beesy day

We've had a lovely, mild, quite sunny day today. Bees came out of their various hiding places and gorged on the garden flowers. Top bee magnets were the hardy geraniums and the hedge woundwort. At least one old Osmia rufa was still about, very late for this spring species. The first Anthophora furcata of the year turned up, at the usual time of the year. She fed on Hedge Woundwort (above, note how thick the bright red tail looks) and Iris. A male was also about.

Bombus pascuorum entering Iris.

 The only B. lapidarius I saw today

Osmia caerulescens female sunbathing

Competition for the hardy geranium, Bombus hypnorum and Osmia rufa

Osmia rufa leaving hardy geranium, note the visible 'horns'

Megachile centuncularis on Bird's foot trefoil

 Bee list

1. B. hypnorum hardy geraniums, cotoneaster. Males and Queens about.
2. B. pascuorum foxglove, purple toadflax, hedge woundwort.
3. B. hortorum foxglove, hedge woundwort, lamium maculatum
4. B. terrestris, Stachys byzantina, trying to feed on Lamium maculatum
5. B. lapidarius poppy, just one.
6. B. pratorum hardy geraniums, cotoneaster
7. Megachile willughbiella male on thyme, stachys
8. M. centuncularis birds foot trefoil, hardy geraniums
9. Anthophora furcata male patrolling, 1st female of yr., Teucrium, Iris, Hedge woundwort, Herb robert.
10. Osmia rufa, hardy geranium
11. O. caerulescens, sunbathing
12. Honeybee Philadelphus

Melecta, a cleptoparasitic bee

The plum tree started flowering last week and today it was buzzing with bees. I counted six species, Bombus terrestris and lapidarius queens, Anthophora plumipes males and females, Andrena fulva, with males actively patrolling the branches, and the first males Osmia rufa of the year. Later, a black bee with white and grey hair patches and dark wings turned up. It was Melecta albifrons, a cleptoparasite of A. plumipes. I haven't found much information on M. albifrons so the following life history account mainly comes from a study on the American species, Melecta separata. Melecta females parasitise Anthophora species that nest communally. They explore their host's nesting aggregations in search of finished nests. A female, upon finding a nest will start digging and breaking open the sealed entrance. Then she will lay an egg on the roof of the cell, seal the cell and replug the nest. Anthophora females usually attack the cuckoo bee, but she either flies away or if inside the nest it defends herself with her sting. The Melecta larva hatches a day earlier than the Anthophora's and is very mobile. They pierce and drain the Anthophora egg and any other Melecta eggs that she finds in the cell with their long sickle-shaped mandibles. Only one Melecta larvae survives, as if two are born at the same time one will kill the other. The larvae then feeds on the syrupy mixture of pollen and nectar intended for the Anthophora larvae. Subsequent larval stages lack the long mandibles of the first stage. The following year a Melecta will emerge from the cell, having consumed the food intended for Anthophora grubs. In a M. separata nesting aggregation 20% of the nests were parasitized.
The Melecta albifrons visiting my plum showed a very different behaviour from other bees, sluggish, like she didn't want to fly too much, climbing over the flowers to reach each of them and feeding showing a very long tongue. The bee stayed for quite a while feeding on the plum flowers. M. albifrons has a very similar distribution to its host in Britain (click here for distribution map), reaching up to the Yorkshire Wolds in the north. Its peak flight period is a few weeks after the emergence of the host, and flies from April to early June. Given that it doesn't need to collect pollen for provisioning its brood, the bee is not fussy about what flowers to visit, and tends to fly at short daily periods - the warmest - as they are less endothermic than their Anthophora hosts, as shown in the figure below.

References
Thorp, R. (1969). Ecology and Behavior of Melecta separata callura (Hymenoptera: Anthophoridae). American Midland Naturalist, 82 (2) DOI: 10.2307/2423782
P. G. Willmer and G. N. Stone (2004). Behavioral, Ecological, and Physiological Determinants of the Activity Patterns of Bees. Advances in the Study of Behavior, 34 , 347-466 : doi:10.1016/S0065-3454(04)34009-X

Mating red-tailed bumblebees

Amongst bees, bumblebees have very long copulations when compared to honeybees and solitary bees. Up to three hours have been recorded for Bombus lapidarius, the Red-Tailed bumblebee, closer to half an hour for B. terrestris. I came across these paired Red-Tailed bumblebees (above) yesterday in the wildlife garden. The brightly coloured, smaller male was simply riding the female, and she bumbled along, feeding on knapweed and heavily flying between flower heads. Females would be expected to be very vulnerable to predators during this time, where they are also very obvious. Although they can actually fly, slowly and clumsily, their sting is immobilised by the male's genitalia. Illustrating this increased vulnerability, the couple of the same species below was squished on a busy pavement last summer.

Why do bumblebees mate for such a long time? Could it be that they need a long time to successfully inseminate the queen? Apparently not, as successful sperm transfer happens in a few minutes when it has been measured. Another reason, is that males transfer not only sperm during copulation, but a 'copulatory plug', which physically hampers further copulation by the female and includes chemicals that make her unattractive to other males for several days, although apparently this plug is also transferred in a matter of 10 minutes. A lengthy copulation might also include the time necessary for the sperm to travel to the female's spermatheca, so the male would be increasing his chances of paternity by guarding his partner. Due to the dangerously long copulation, the copulatory plug dissuading further partners, and the still puzzling effects on her hibernation success and colony fitness due to multiple mating, Bumblebee queens only mate once, with one of the few exceptions being the tree bumblebee (Bombus hypnorum).

More information:
Brown, M., & Baer, B. (2005). The evolutionary significance of long copulation duration
in bumble bees. Apidologie, 36 (2), 157-167 DOI: 10.1051/apido:2005008

Making cherries

We've got a small cherry tree in our garden. In addition to making a spectacular show when it blooms, it produces the sweetest cherries and, although the crop can be a bit hit and miss depending on the spring weather, it is a bug magnet for a few months. The tree only started flowering a week ago but today was buzzing with bees. I spent some time this morning watching the blossom and trying to ID the bees that are feeding on it or visiting. Anthophora plumipes and Osmia rufa males have incorporated the tree into their patrolling routine, circling around the blooms, chasing other bees and keeping track of the females. Beautiful, velvety shiny red female Andrena fulva were also feeding on it as were female A. plumipes. I stopped counting the honeybees as there were quite a few. To the high pitched buzz of the Anthophora bees, the deep buzz of queen Bombus lapidarius and Bombus terrestris was added. These busy lot of creatures were involved, without realising it, in fertilising the blossom and contribute to making the cherries that hopefully we'll eat this summer.

Peacock butterfly

Bombus lapidarius

A full Andrena fulva sunbathing near the tree.

Outside the blooming season, which lasts a few weeks from April to May, the tree growing buds are covered on black aphids that in june produce a sweet sap, loved by bumblebees, especially Bombus terrestris and Bombus hypnorum. I have also seen Bombus pratorum feeding on the nectaries at the end of the leave stalks. Aphids also attract scores of ladybirds. The cherries themselves are prized by wasps - and birds.

The end of summer

Autumn is quickly approaching. The leaves on some lime branches are already yellow and a few brown leaves rustle on the ground. The squirrels have dropped some early conkers they have nibbled. But today is a bright, warm day, with lots of butterflies. A Speckled Wood was sunning itself in the park and a Comma, a Small White and a Large White visited the garden in the morning.

We walked past one of the last buddleias in good bloom. It is now the end of the buddleia flowering season and this particular bush teems with butterflies today. I count six Red Admirals (probably already migrating south) , three Small Tortoiseshells (ready to hibernate) and a Large White.

One Small Tortoishell fed on the dandelions amongst the grass.

Other insects included a queen Bombus lapidarius, velvety black and red feeding on Agapanthus, and B. pascuorum, the most common bumblebee these days, on Sedum spectabile (below).

Lots of Araneus diadematus. One five-legged male creeps close to a female's web.

Another female nearby spins its web.

The large ivy is not flowering yet, although it's got lots of buds.