I have spent some time watching mature Ivies lately. It is Ivy peak flowering season, and the couple last days have been warm and sunny, bringing the insects out, the ivies humming with insect activity. Droneflies, Red Admirals, Comma, Wasps, honeybees are attracted to flowering bees. I was actually looking for Green Mesh Weavers, on an Ivy in an untarmaced tenfoot (alleys between houses) when I noticed two stripy bees rummaging around the leaf litter at the bottom of the ivy. I couldn't believe they were Ivy Bees, Colletes hederae! I have previously seen Ivy Bees in east Yorkshire, at North Ferriby and at Flamborough, but I thought we wouldn't get them in Hull due to our clay soils, as this bee needs loose soils for nesting.
Two bees exploring the soil under the ivy, this is probably loose enough and sunny enough for a nest site?
A winner from climate change
Ivy Bees started colonising the UK from 2001, after expanding in northern Europe, and in the last couple of decades its distribution range has rapidly expanded northwards, with the first Scottish records coming in 2021. The mail pollen source for its larvae is Ivy, and the bee flight period coincides with the flowering season of ivy, from September to early November, with a single brood. They are solitary bees but they tend to nest together, sometimes forming large nesting aggregations in suitable habitat. Females will excavate a nest and line the walls with a cellophane-like substance, which explains another name of the bee, Cellophane Ivy Bee. Ivy pollen is brought to the nest and an egg is laid atop a mound of pollen, before the cell is sealed and another load of pollen is collected for the next egg.
One of the Ivy Bees near the ground after some exploring.
A female laden with pollen having a rest to clean its tongue.
A foraging female showing the banded abdomen. This bee is relatively large, the size of a honey bee, with orange hairs on the thorax, and contrasting broad buff bands in the abdomen, unlike its close relative the Sea Aster bee, which is smaller and has a white banded abdomen. Habitat, timing and foraging flowers can also help distinguish these bees.
After a warm couple of weeks the temperature dropped suddenly on Tuesday and we've had quite a long of rain. From the conservatory window, I noticed a roosting Wool carder bee (Anthidium manicatum) on a Purple Toadflax flower spike, one of their favourite flowers. As I took a photo I saw there were actually three others roosting nearby, all females. Today it was far too cold for them to be active, so they are braving the weather holding onto the flowers with their jaws, so when the sun shines again they should be ready to feed straight away.
Although we've had a few poor years for wool carder bees, this year they have come back en force and two males have been defending their territory in the garden.
Spot the roosting bees. A carder bee, Bombus pascuorum, feeds on the flowers unmolested. Bumblebees generate their own body heat and their dense hair coat helps them retain it so they can be active at lower temperatures than the wool carder bees.
Many flowers, closely protect their nectar in deep nectaries (e.g. the Mint family) or behind barriers made by modified petals, like pea flowers. This way, unspecialised nectar feeders, which may not be good pollinators such as ants might not be able to access the nectar, but bees, which will visit many flowers in succession and are effective pollinators will be able to. These modified flowers have their pollen-bearing anthers on the roof of the modified petal blocking the entrance. The bee, while coming in to feed on the nectar, rubs its back on the pollen, ensuring she will pollinate the next flower she visits. Bees, however, often have to work really hard to get at the nectar.
A few days ago I watched a common carder bee, Bombus pascuorum, feeding on Iris flowers (top photo). It tried to get in through the side unsuccessfully, but eventually found the way in pushing through the middle of the landing petal (which are called 'falls').
Later, a female Osmia caerulescens, landed on a Phlomis flower, she seemed to sense there was nectar behind the hooded petal closing the flower and pushed with her head until it managed to get under it. It spend quite a long time inside, I guess this is a nectar-rich plant and it will take a while to empty the nectaries for a small bee like this.
Osmia caerulescens getting in.
The bee just before leaving the flower after feeding.
There was definitely a buzz in the garden today. The usual Anthophora plumipes males were now joined by the first female of the year (above), feeding on the Pulmonaria. The Pulmonaria, unfortunately, was in the shade, so I couldn't take as sharp photos as I would have liked. A male Osmia bicornis (previously rufa) was patrolling the grape Hyacinths and a female Andrena fulva made a brief appearance. Just on cue, as the Cherry, a favourite of this bee, started to bloom yesterday.
A Green Shieldbug was out sunbathing, also the first of the year. Many young wolf spiders were out too in the sun, stalked by my young cat, who likes to hunt and eat them, to my dismay. A Peacock butterfly passed by, but didn't settle.
Bee hotels are very popular at the moment. Most garden centres sell them, and they are advertised as homes for solitary bees. Solitary bees do use these bee hotels to make their nests, but once you get guests, how to tell them apart?
I was inspired to write this post after a twitter exchange starting with this message:
There appear to be about 225 species of solitary bee - think id unlikely!!! But so pleased something is using bee box :)
— Ragged Robin (@CarolineIrwin3) July 13, 2013
With this post, I hope to give you an overview of what species of bees are likely to use bee hotels. In fact, only a small number of the over 250 species of solitary bees in the UK are likely to use bee hotels, so, with a bit of patience, identification is likely. For a start, not all solitary bees use bee hotels as they do not nest in cavities. Many solitary bees nest in the soil (the mining bees), others prefer the mortar of walls, or dig their nests in dead wood, or prefer much smaller holes or crevices than those provided in commercial bee hotels, which are usually made out of bamboo or reed canes. Mind, you, many more solitary bee species will be found in your garden than the ones that use the bee hotel. Once a female bee choses a tube in the bee hotel for nesting, you are likely to notice some activity, as she stocks the nest with nectar and pollen, lays eggs and builds partitions between the cells where her offspring will grow. Once she runs out of space in one tube she makes a stout plug and may start to fill another tube with more cells. The males searching for females or patrolling the area of the bee hotel can also bee noticeable.
In addition to bees, other insects like some digger wasps or the cuckoo bees or flies that parasitise the bees themselves or spiders will also be seen on or near the bee hotel. My experience is on the north of England, and with home made bee hotels made by drilling holes in pieces of wood, so it is likely a few more species will be found to use bee hotels in the south.
For identification purposes, time of the year, general size of the bee (use a honeybee as a guide) and colour patterns are useful. Also, it is very helpful if you can check what the bees are carrying as nest materials and the colour of the brush of hairs under the bees' abdomen that they use to carry pollen. The material of the plug covering the finished nests can also provide information as to what species built it. Once you can recognise the species or species group of the bees using your hotel, they are bound to provide an endless source of fascination, and bee watching may be addictive, so make sure you place your bee hotel in a spot you can easily and comfortably watch at close quarters!
Red Mason Bees
These are likely to be the first bees in spring using a bee hotel and the most likely species to use bee hotels. The bees are active from March to May. The females are reddish, with large, black heads, and size similar to honeybees. They have characteristic 'horns' on their faces, which they use to mould mud (above). Males are also reddish, smaller and with a white moustache. Males often sit on or near the bee hotel, sunbathing and looking for females.
Mason bees use mud to partition cells in the bee hotel holes. They will travel from the bee hotel to the edge of ponds where they fetch mud, a little pellet at a time. Click here for more posts on Red Mason Bees in BugBlog.
Blue Mason Bees
These are much smaller bees and there are two similar species, Osmia leaiana and Osmia caerulescens (the blue mason bee proper). Males of both species are metallic green. They like to sit on the nest or stones or leaves at low level to sunbathe and from there they do patrolling flights in search of females. The females are metallic dark blue with a dark pollen brush underneath (O. caerulescens) or dark brown with an orange pollen rush (O. leaiana, above). Both species use chewed leaves to partition their cells.
Leaf-Cutter Bees
These are high summer bees, flying from mid May to August. I have two species in the garden, a large one and a small one. There are other common species in the UK, so care should be taken with identification. The male of the large species, Megachile willughbiella, is easier to identify, as it sports white-golden mittens on its front legs, which are very visible as he sits on the nest or sunny spots and grooms himself. Other identification features are the colour of the pollen brush on the underside of the abdomen: either orange (in the smaller species M. centuncularis, above) or red and black in M. willughiella (below). It is worth checking your bee hotel in poor weather, as these sun-loving bees like to use it as shelter in cold or wet conditions. More on leaf-cutter bees in BugBlog.
Female Megachile willughbiella. Note the red and black brush of hairs under abdomen
Megachile willughbiella male. Note the pale 'mittens' on his front legs.
A few photos of the looks of the finished nests follows.
TwoM. willughbiellamales with twoOsmia rufa (grey mortar looking) and a O. leaiana/caerulescensat the top, which is made of chewed leaves).
A completed nest of a leaf cutter bee, Megachile. They use circular sections of leaves to make their nests.
Two recently completed nests of Osmia leaiana/caerulescens (I suspect the former, which in the last few days has been feeding on knapweed). Photo taken today.
The same area of the bee hotel on the 11th of May, just an Osmia rufa nest had been completed then.
Other bees that are known to use bee hotels in the UK are Chelostoma florisommne and Chelostoma campanularum, other Megachile species and Ectemnius digger wasps.
Ectemnius sp. a digger wasp, emerging from its nest.
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
B. hypnorum hardy geraniums, cotoneaster. Males and Queens about.
B. pascuorum foxglove, purple toadflax, hedge woundwort.
B. hortorum foxglove, hedge woundwort, lamium maculatum
B. terrestris, Stachys byzantina, trying to feed on Lamium maculatum
B. lapidarius poppy, just one.
B. pratorum hardy geraniums, cotoneaster
Megachile willughbiella male on thyme, stachys
M. centuncularis birds foot trefoil, hardy geraniums
Anthophora furcata male patrolling, 1st female of yr., Teucrium, Iris, Hedge woundwort, Herb robert.
I have always wanted to see a Bee Fly (Bombylius major). Yesterday I had a glimpse of one in the garden, but being unable to get a photo I later thought that I had mistaken a bee for one of them. Today, early in the morning, probably the same one came to bask on the wall, flying amongst two Anthophora plumipes males, and I had my camera with me. The bright white background wasn't ideal, but I was happy enough to get a few shots. Bee flies are bee mimics, with furry brown bodies of about 12 mm long and their proboscis is almost as long as their bodies and they carry it sticking out forward while they fly or at rest. They are very good flyers and feed while hovering. Males and females feed on nectar, but females also need to feed on pollen to produce eggs. Their long proboscis, which is also adapted for sucking and it is quite movable, allows them to exploit flowers with deep corolla tubes, such as primroses, Aquileguia, lungwort, grape hyacinths and wallflowers, and they are important pollinators of them. I wonder if the abundance of these flowers in my garden, which I grow to attract A. plumipes, has been a factor in attracting the Bee Fly to the garden.
Bee Fly larva are ectoparasites of ground-nesting bees, (the genus Andrena, Halictus, Lasioglossum and Colletes have been reported). Bee Fly females lay their eggs dropping them in or nearby the tunnels of bees, even on flowers if the female can't find suitable nests. When the larvae hatch they either find the nest and go into an open cell, or latch themselves to a passing bee when they hatch on flowers.
Summer finally arrived a dew days ago, and the bees have been enjoying the sunshine and warmth. I have been busy beewatching. It struck me that although there are hundreds of birdwatching books available, 'Beewatching' is not a shelf you will find in your trip to the library: number of beewatching books: nil, zilch, zero (sorry, no, I do not mean beekeeping). But why? Although bee watching has challenges, it is immensely rewarding. Plus points: (1) you can do it from the comfort of your garden, in fact gardens are amongst the best habitats to observe bees, as many flowers are available and you can pop out when weather conditions are optimal, therefore, no transportation needed (2) no binoculars or telescopes are necessary, and, (3) with a little investment on garden plants or a home-made bee hotel, you can be rewarded by new species coming to you and behaving as they do in the wild and even breeding in your garden: even small urban gardens can attract a large number of species. Given the lack of field guides on the topic, beewatchers are forced to made themselves out of experience, plenty of patience and readiness to learn. Although many bee species can only be identified under the microscope, some common garden species are relatively easy to identify while they are going about their business. I hope to show here that you can narrow down the group of bee or even identify to species level solitary bee species just by watching the various activities they are engaged with.
Watch the flower
Many bees prefer to visit particular flowers. Some bee species are oligolectic, which means that they gather their pollen from one or a few flower species, others called polylectic, collect pollen from a wide variety of flowers. But even if the bees are polylectic, they often show some degree of preferences, therefore noting which the flowers they are visiting makes it easier to identify bees. This works even for males when they are patrolling and not feeding, as the males will check out the flower species that the females visit for nectar or pollen. A male Anthophora furcata, today, checked first one patch of Stachys sylvatica, then Lamium maculatum, then the other Stachys sylvatica patch. Surely, a female appeared later (below) to collect pollen in S. sylvatica, and the orange pollen she was carrying was probably from Lamium.
Wool Carder Bee females are likely to be spotted shaving Lamb's ears (Stachys byzantina) hairs or feeding on the flowers. Megachile willughbiella loves cranesbills, campanulas and everlasting peas. Anthophora plumipes is strongly attracted to Lungwort and Comfrey. It also works the other way round: some plants are visited only by a reduced number of species: only a handful of garden species will visit foxgloves or honeysuckle.
Pay attention to detail
A large male bee patrolling campanulas is probably a leafcutter bee, Megachile willughbiella. To make sure, follow him as he flies, as he will settle regularly in a sunny, exposed place after bouts of patrolling (below).
Watch him carefully when he stops, he will almost invariably groom his head with his front legs a couple of times after landing - why? maybe wiping his eyes clean? -, and his white 'boxing gloves' will be visible even from a couple of meters away. If you can get closer, crouch down and look at him straight in the eye: he is all concentration, watching for females, rapidly twitching his head looking left, right or up. He does this for a few seconds and then flies off to carry on patrolling. Leaf designing
A little bee flying from leaf to leaf, settles and walks sideways along the edge of the leaf briefly, like she is checking it, flies to the next leaf and then starts cutting an oval shape piece with her jaws.
Just finishing cutting the piece. Note that the same leaf has two other cut pieces.
In this shot you can see how she is holding the rolled piece of leaf with her legs and jaws
The edge of most leaves of my Enchanter's Nightshade plants, are all cut out. The culprit is the aptly named leaf-cutter bee, Megachile centuncularis. Leaf cutter bee females collect hundreds of leaf fragments to line their nests. As she cuts a fragment, she rolls it under her body using her legs and when she is finished she also holds it with her jaws before she flies up and then straight to her nest. If you can check the underside of her abdomen as she cuts the leaf, you will see the golden brush that characterises this particular species. Spot the bully
I watched the first Wool Carder Bees of the year a couple of days ago in the local wildlife garden. Two males patrolling and feeding in a patch of Betony.
These are large, powerfully built bees, armed with five sharp prongs at the end of their abdomen. Males are territorial and they will readily attack and expel from their territory any other bees - even big bumblebees -, monopolizing the females that come to feed at their patch. When they rest, they keep their wings open at an angle, with their abdomen exposed. One of the males attacked a Bombus pascuorum feeding on the betony, and the bumblebee swiftly flew away.
Bottoms up!
Watch how the bee feeds on a flower. Leaf cutters (Megachile species) carry their abdomen tilted up, especially females, and rotate on the flower collecting pollen (see top shot). Look under their abdomen, you will see a broad brush of hairs. The color of the brush can help identify the species. They collect pollen on their rear legs and transfer it to the brush as they move over the flower. Megachille willughbiella females have a red and black brush, while M. centuncularis have an all golden one. Note that the hair color can be obscured by the pollen! This little video I took earlier today shows how she collects pollen on knapweed, a current favourite plant for bees in the garden.
Don't forget the little ones
Many bee species are small, you might have taken them for small flies in the past, but now that you are watching flowers up close you start to notice them. These two photos show flower preferences in two small Osmia species, which I only found in the garden this year. How could I have missed them before?
Osmia caerulescens, the Blue Mason Bee, likes labiates like French Lavender, Sage or hedge Wouldwort
Osmia leaiana loves Knapweeds
Watch the seasons
Solitary Bees fly during relatively narrow periods, maybe two or three months in the species that have a single generation per year, so the time of year is often informative. Anthophora plumipes flies from March to early June, whereas Anthophora furcata has a short flying season in June and July. There is so much to learn
As you become a beewatcher, you will develop a thirst for learning about the lives of these little critters that share your garden. For some of the species there is little information available, even common species have structures or behaviours that still remain enigmatic (what is the purpose of Megachile willugbiella boxing gloves or Anthophora plumipes hairy legs? why are the scopas of bees different colours, do they provide information to other bees, maybe when mating?). There are some resouces that I treasure, like my Bees of Surrey book by David Baldcock, or the BWARS site, and various bee identification forums, but as these are mainly concerned by identification and recording, I still want a beewatchers field guide.
A warm morning of sunny spells, bees come out en force. A Cuckoo bumblebee, possibly a male Bombus vestalis (above), a cleptoparasite of Bombus terrestris fed on the Erysimum Bowles Mauve. Bombus pratorum workers and males are feeding on many flowers, Centaurea montana, Chives and Herb Robert, surprisingly also Foxgloves and also nectar robbing the Comfrey.
A couple of queen bumblebees, Tree (above) and Buff Tailed bumblebees feed together on the patch of Red Valerian for a long time.
On the Oxeye Daisies, a Lasioglossum sp.
The first leaf-cutter bee, Megachile willughbiella, of the year feeding on Erysimum. I also saw it on the geraniums.
Wall Rocked receives a visit of a very worn Andrena
The new Osmia caerulescens are now everywhere. The males have been checking the bee post. In the next shot, a male stretches its tongue, amazingly long. No surprise its preference for Sage and Lamium maculatum in the garden.
This female sunbathing next to the Sage shows why they are called Blue Mason Bees
The summer bees overlap on early June with the last of the spring bees. An Anthophora plumipes female was briefly feeding also in the amazingly popular Erysimum. Finally, Red Mason Bees, Osmia rufa were abundant. Overall 11 species, not counting honeybees. A wonderful morning bee watching!
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