Nectar from cherry leaves

I was watching male bumblebees around the cherry tree a few days ago when I saw some honeybees around. On close inspection, I noticed they were visiting extrafloral nectaries, little red swellings in the petiole of cherry leaves, which secrete nectar, usually taken by ants. The bee would visit several leaves in succession, but being high in the tree, it was tricky to get good shots. I noticed an early bumblebee, Bombus pratorum, doing the same. So, even when not in bloom, cherry trees are producing nectar used by bees and bumblebees. Many other plants have these nectar glands, including willows, cherry laurel and plums.

honeybee sucking nectar from the nectary

Male Bombus pratorum doing the same

A close up of a cherry extra floral nectary

Early wool carder bees

This year much buglife has been appearing earlier in the season than last. Wool carder bees haven't bucked the trend and I saw the first male, yesterday, large, aggressive and bossy from the start, patrolling the sunny herb patch in my local Wildlife Garden. I came back today for more bee watching and better shots and females were also out. The main object of the resident male's attentions is a patch of Hedge Woundwort, Stachys sylvatica, a native plant close relative of Lambs ears, S. byzantina. Both are hairy plants of the mint family, the native one less so, and so favoured as food and wool plants by the female Wool Carder bee. The male knocked a bumblebee down to the ground and proceeded to watch a female while she fed, and attempted mating. He followed the female closely around the Stachys patch, hovering a few inches behind her (above). When she left, he moved around the patch, hovering in places, changing his body orientation, watching every moving thing that dared approach his newly founded chiefdom. He stopped to rest on a sunny leaf every now and then, all the time watching, vigilant.

The female feeds on Stachys sylvatica

Male Wool Carder bee resting

Encounter with a Lime Hawkmoth

Our street is lined with lime trees and occasionally, in mid August, we come across the wandering caterpillars of the Lime Hawkmoth, Mimas tiliae, as they leave the trees and get ready to bury themselves under the soil to pupate. I have very rarely come across the adult, but this morning my son found this fresh, magnificent male on his spade. The moth stayed put on some Herb Robert all day, waiting until I came back from work. Were not for the fact that we knew exactly where it was, its amazing camouflage, with a patchwork of dark green and pinkish shades and scalloped wing edges, would have made him pass unnoticed. This species has increased its range and is distributed through most of England. Adult lime hawkmoths fly in May and June and do not feed, their only purpose in life is to find a mate.
 I couldn't resist and had to take some shots on a whit(ish) background. On close up, the antenna and red front legs are very apparent.

Tonight, the male will probably fly in search of a female with the help of his feathery antennas.

Bees in ponds

When you think about a pond, bees do not normally spring to mind. Bees, however, need water. In sunny days honeybees travel in numbers to water sources to take water to cool down their hive, and they also use it to dilute honey to feed their larvae. These three were drinking by the edge of the pond in my local wildlife garden, near their hive.

On the other side of the pond edge there is a muddy site. Several female Red Mason Bees (above) were collecting mud to line and cap their cells. A female would dig up the mud and shape it with the  help of her jaws and two little facial horns into a little ball, and then fly to the nest holding the ball in her jaws. It took me a few attempts to get a half decent shot.

Osmia rufa female with her ball of mud

Racing male tree bumblebees

In the last two weeks, the garden has been overtaken by frenzied male bumblebees. They follow a set circuit, round and round, racing from bush to bush and then having a little bumble in each. If you wait for a bit on a particular spot on the route, you are likely to see another bumblebee a few minutes later passing by in the same direction, doing exactly the same. Most of the males I have been able to identify doing this are Bombus hypnorum. Today, a male B. hypnorum - which can be distinguished from the female by his white moustache - got trapped inside the conservatory and I had his portrait taken (above). Many male bumblebees have recently emerged from their nests, never to return, and their mission is to find queens and mate with as many as possible. In many bumblebee species, males' strategy consists on tracing a route, sometimes hundreds of meters long, often circular, depending on the species, and marking certain places along the route with pheromones produced by scent glands in their jaws. Males join already set routes and therefore many males, some of them probably their siblings, go round the same routes every day, stopping to feed occasionally. Queens encountering a route are attracted by the pheromone and are then intercepted by males. The discovery and first description of these male bumblebee flight paths - from Bombus hortorum males - dates back to Charles Darwin, from observations he carried out at Down House. Although he didn't realise pheromones were involved, he noticed bumblebee routes and them stopping and bumbling at places he called "buzzing places", and marveled at the fact that the same or very similar routes were used year after year:

I then followed their route for about a hundred and fifty yards until they came to a tall ash, and all along this line they buzzed at various fixed spots. At the far end, near a pollard oak, the track divided into two as shown in the plan. On some days all the bees flew in the direction I have described, but on others some arrived from the opposite direction. From observations made on favourable days, I think that the majority of individuals must fly in a wide circle. They stop every now and then to suck at flowers. I confirmed that whilst in flight they move at about ten miles an hour, but they lose a considerable amount of time at the buzzing places. The routes remain the same for a considerable time, and the buzzing places are fixed within an inch. I was able to prove this by stationing five or six of my children each close to a buzzing place, and telling the one farthest away to shout out " here is a bee " as soon as one was buzzing around. The others followed this up, so that the same cry of " here is a bee " was passed on from child to child without interruption until the bees reached the buzzing place where I myself was standing.

  This sketch of the grounds of Down House shows the part of the male bumblebee flight route studied by Darwin with the help of his children. What fun must have been to have him as a dad!

References

Freeman, R.B. (1968). Charles Darwin on the routes of male bumblebees. BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) HISTORICAL SERIES , 3 (6), 177-189.


Stiles, Edmund W. (1976). Comparison of Male Bumblebee Flight Paths: temperate and tropical. Journal of the Kansas Entomological Society., 49 (2), 266-274.