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.

Flies and bees

The morning started chilly, but when the sun appeared in the middle of the day I peeked out of the conservatory and saw a male Anthophora plumipes, the first of the year, stopping on a stone by the rosemary to sunbathe. It patrolled the garden and briefly settled to feed on the lungwort. I watched another male in a front garden in my street later in the day.

Male A. plumipes feeding on Pulmonaria officinalis.

A bit of hovering...

...and a bit of basking.

  On a south-facing Clematis montana in bloom I found a couple of honeybees and a hoverfly, Syrphus ribesii (top shot).

And in my local wildlife garden, a queen Buff-tailed bumblebee searched for a nest site.

It is the start of the bee season and I shall take my macro camera with me from now on in my outings.

Sunshine at last

After stormy, windy and very dark days, there were some long sunny spells on monday and I came across several stirring insects during my daily wanderings. A cold queen Bombus terrestris on the windowsill, with the tiny sprightly springtail, Entomobrya sp, possibly nivalis, on a walkabout around her.
 Then I disturbed a moth in the front garden, the plume moth Amblyptilia acanthadactyla.
But the best find was a very fresh looking peacock settled on the pavement by a fence, with is pictured at the top of the post.

Entomobrya sp.

Bombus terrestris queen.

The plume moth Amblyptilia acanthadactyla

Mating buff-tailed bumblebees

Next to a busy road, by the base of a tree, surrounded by concrete and oblivious to the noisy traffic, this pair of White-tailed bumblebees were mating this morning. The queen lying motionless, a bit sideways, the male tickling her rhythmically with his legs. I have been taking some videos with my camera lately to record some unusual, or more common bug behaviour. I hope this works as it is the first time I upload a video to BugBlog.

* * *

I wrote the piece above almost 5 months ago, on the 19th of July, when I saw the bumblebees mating. I tried, and miserably failed to upload a video to YouTube. Here it is, finally posted. Thank you Crystal Ernst! More to come.

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

November bug magnets

I went for a walk this afternoon to re-acquaint myself with my clean and repaired camera. After spending almost three weeks camera-less, it was great to have it back. I just walked back to the spot where a few days ago I spotted the B. hypnorum and waited around the sweet smelling Mahonia bushes trying to spot more bumblebees. There were flies (Bluebottles and a smaller species) and wasps around, but my patience finally paid when I saw the distinctive large and dark shaped of a bumblebee amongst the flowers. Not a B. hypnorum, but a worker B. terrestris, stayed just for a few shots (top).

 The second bug magnet today was Ivy. There were dozens of male wasps feeding on Ivy flowers on the wildlife garden. Their large antenna reminded me of mountain Ibex males. I am not very good identifying wasps, although in a post in WAB today somebody pointed at a very informative webpage to identify them. I will update the post if I manage to get an ID. Around the ivy there were also feeding Bluebottles and a parasitoid wasp.
 The third bug magnet was a non-native bush related to the Ivy, the Fatsia japonica. Here the ubiquitous bluebottles were the only insects around.

Flower engineers

Yesterday I was following a queen Bombus terrestris, as usual, with the faint hope one will nest in my garden when she landed on a comfrey patch. This was the first time I have seen this species on comfrey, their deep flowers are mostly visited by Bombus pascuorum, B. hypnorum and B. pratorum*, in addition to Anthophora plumipes. The heavy queen landed on top of the flowers, and I was able to approach without disturbing her. She noisily bit the top of a flower and then inserted her tongue on the resulting hole. She then moved to another flower and repeated this behaviour quite a few times before leaving the patch. I was too fascinated watching and I didn't take any photos, fortunately, forensic evidence was left behind and I could take a shot of the actual holes easily spotted in the flowers (above). This queen was engaging in 'nectar robbing', a not uncommon behaviour amongst Bombus terrestris, by which individuals can feed from flowers where nectar is not accessible via the corolla opening. Flowers that are 'robbed' might have a complex floral morphology adapted to attract specific pollinators - for example, nectar can be located in a deep spur; or flowers might have lips that need force opening for entering, or the corolla could be just too deep to reach the nectar inside. Nectar robbing - described by Darwin - is another of the aspects of the foraging repertoire of B. terrestris, which, despite its short-tongue it is an impressively resourceful species. Research has shown how queens learn by experience where exactly to perforate the flowers to reach the nectar optimally, and how they switch to use previously made holes to feed when the proportion of perforated flowers reaches a threshold (secondary nectar robbing, of which honeybees and other bumblebees also benefit).

 Surprisingly, and despite its negative name, nectar robbing is not necessarily detrimental to the plant. The studies comparing seed set on 'robbed' vs. normally visited flowers in bumblebees show that either there is no effect on seed set or an increased seed set when 'robbed', indicating that nectar robbers are indeed involved in pollination. In addition, nectar robbing can happen at the margins of the plant distribution, where the usual long-tongued pollinators might be absent and the 'robbing' could be the only chance for seed set in self-incompatible species. Although to avoid this 'robber-like pollinators' has been proposed, I myself thin that a more suitable name for hole-making bumblebees could be 'floral engineers'.

A B. pratorum feeding on comfrey. Despite its short tongue it feeds via the corolla opening, I guess it must be able to reach the nectar due to its small size, maybe able to stick its head into the corolla itself, or it might be just collecting pollen. B. pratorum has also been reported as a primary nectar robber.

Bombus pascuorum feeding on comfrey flowers through the corolla opening

A close up of a Bombus terrestris queen showing her powerful set of mandibles

More information
Olesen, J.M. (1996) From Naïveté to Experience: Bumblebee Queens (Bombus terrestris) Foraging on Corydalis cava (Fumariaceae) Journal of the Kansas Entomological Society, 69, No. 4, Supplement: Special Publication Number 2: Proceedings of the Eickwort Memorial Symposium (Oct., 1996), pp. 274 -286. http://www.jstor.org/stable/25085724

Goulson, D., Stout, J., Hawson, S., & Allen, J. (1998). Floral display size in comfrey, Symphytum officinale L. (Boraginaceae): relationships with visitation by three bumblebee species and subsequent seed set Oecologia, 113 (4), 502-508 DOI: 10.1007/s004420050402

Maloof, J., & Inouye, D. (2000). ARE NECTAR ROBBERS CHEATERS OR MUTUALISTS? Ecology, 81 (10), 2651-2661 DOI: 10.2307/177331

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.

Bug overload!

These days I find it difficult to settle on a topic for the blog. We have gone from long bug-poor weeks of indoor seclusion through the long harsh winter to a month of March when things seem to happen too quickly. So I am writing posts more alike to my nature notebook, which, by the way, was the original intention when I started. We had a lovely sunny, mild day today and I pottered about in the garden bug-watching and took a couple of local walks. Even when doing the shopping I came across bugs worth posting about. What to choose? I just can't.

Small Tortoiseshell on willow

A male Anthophora plumipes hovering

The morning started by my discovery of a bug magnet in a neighbours garden: a flowering willow. The large bush was teeming with bumblebees, all of the ones I could see were Bombus terrestris. A Small Tortoiseshell, the first one this year, feed in the catkins and several Anthophora plumipes males were hovering around ramming every now and then both the butterfly and the bumblebees. I took a few pictures but I wasn't close enough for good ones. I had to stop myself from picking up the binoculars, though, to watch the activity at close range. Nectar-feeding insects prefer to visit sources where flowers are in large masses, so that they save energy looking for the next source. Willows in early spring provide a large number of flowers where typically there are not many other species flowering, so they are sought after my many bees and bumblebees.

 A brimstone passed by flying over the gardens. This is my typical brimstone sighting, early spring, fluttering past, never stopping and I rarely see them again the rest of the year. A frustrating butterfly! The following photos illustrate other sightings.

A beautiful Harlequin sunbathing

A couple of mating 7 spot ladybirds

Baby millipedes found clinging to an old conker

Bug watching day

Around midday, a giddy Peacock - my first butterfly for 2010 - fluttered around the garden until it decided after a good while to settle and enjoy a sun spell on one of my first ground windowsills - which as you can see badly needs painting!. Peacock was also the last butterfly I saw in 2009 (29/10). Almost five months without butterflies is far too long!
 Then, I watched more Anthophora plumipes in the garden. I had seen one of the males patrolling the Tet-a-tet daffodils, but this morning a male actually fed from several of them.

I managed this shot of the male, tongue extended in preparation for landing on a Daffodil.

The male (or males) were feeding today on Muscari, Pulmoraria and the Daffodils. Often they dart to a clump of flowers, hover briefly to inspect them and dash away before I have the chance to press the shutter. Later in my street another A. plumipes was visiting pansies and cultivated primroses (both of them first time I see them visit). So that adds three more flowers to the plants for your 'Flower Bee Garden'.

Seven spot ladybirds and a harlequin were active in the garden, and a queen Bombus terrestris queen visited the garden looking for nesting sites with their characteristic low wandering flight. Two other unidentified bumbles flew overhead.

Third bumblebee of the year

A funny title you'd think. Well, I saw my first bumblebee on the 10th, then another on the 13th (both flying over and unidentified) and today, finally I saw one close enough for identification: a Buff-Tailed bumblebee or Bombus terrestris on a pot. Flew quickly away before I could take out my camera (the photo on top is from october 2008) but at least I got a clear ID. It hasn't been particularly sunny today, but it is noticebly milder, around 10 oC, and things are quickly changing in the garden. The Grape Hyacinth flower spears are pushing through the leaves, box buds are bursting. The two last dormant ladybirds on the monkey puzzle have finally broken their long sleep and are moving about.

Your majesties are back

I had a walk through Pearson Park Wildlife Garden in the afternoon. It was sunny and mild and I was hoping to see the first butterfly, or 7-spot ladybird of the year. There is a lovely flowering heather struggling amongst the fence posts and I checked it. Two beautiful, fresh looking Bombus terrestris queens were lazily feeding on it, accompanied by a drone fly. Note the tawny end of their abdomens, which identifies them as queens. This large heather must be such a priced source of nectar and pollen at this time of year. I will be more fastidious this year recording the flowers on which I find each bumblebee species and write a blog with my results. Bumblebee watching is one of my favourite activities in the summer with my large lavender hedge and nectar-laden Hebe always humming with them. I have recorded all six common species, at least a cuckoo bumblebee and the new arrival Bombus hypnorum in my relatively small garden.

.

queen number 1

queen number 2