The Red Tailed Mason Bee

You may well have noticed some bees recently. One of the earliest solitary bees to emerge in spring is the Red Tailed Mason Bee, Osmia bicolour. They are very distinctive and make their nests in a very particular place.

The males emerge first, sometimes as early as March. They have yellowish bands. They are the followed in a couple of weeks by females which have distinctive red-banded abdomens, giving this bee its common name. The adults may continue flying well into July, so you have plenty of time to spot them. This species of bee is mainly found across southern England and the Midlands and South Wales. This is because it prefers chalk and limestone grassland and so is mainly in areas with this type of habitat.

Female Red Tailed Mason Bee making a snail shell nest. Copyright © John Walters, used with kind permission.

The Red Tailed Mason Bee is unusual in that the females make their nests in empty snail shells. A female bee works diligently to select a suitable shell then prepare the nest. She will then defend this vigorously. She will make several cells within the spiral of one shell, laying an egg in each cell. She will provide each egg with pollen as food for the larvae when they hatch. She will separate each cell with a glue-like substance called mastic. She makes this by chewing up pieces of leaf. When the nest is completed, she will plug the shell with more mastic and will then search for debris such as grass stems, fallen leaves and pine needles to carefully cover and camouflage it. She may also spread more mastic over the outside of the shell.

Entomologists think it is likely that this behaviour protects the shell and its contents from parasites and predators. Safe inside, the eggs will hatch and the larvae will develop inside the shell, feeding on their supply of pollen. They will then survive the winter as pupae, emerging as the next generation of adults the following spring.

So, if you spot an old snail shell, it’s worth keeping an eye on it; it may just become a nest for a Red Tailed Mason Bee. We’d love to hear about your bee sightings and to see your pictures. Get in touch with us using the comments below or by the Contact Us page.

Header image: Red-tailed mason bee, Osmia bicolor female. Image: František ŠARŽÍK CC BY 3.0

BREAKING NEWS: Once in a lifetime insect emergence

There is a secretive and enigmatic species of moth that will only emerge from their pupa in very specific conditions, on the first day of April. These once in a lifetime conditions are due to be met in the Oxford area today.

The caterpillar of this insect sub species, known as the Lesser April Jester moth (Stulte aprilis dies), will find a sheltered, confined space in which to pupate. In nature, cracks in rocks are an ideal location, but it has adapted to built environments by using the gaps between paving stones. Here it will stay, for years or even decades, until the required environmental conditions are met. When a cold snap follows an unseasonably warm spell, the adult will emerge from the pupa. Entomologists from Oxford University Museum of Natural History believe that the weather we have experienced recently meets these conditions, and is the best chance to see emerging adults for several decades.

Specimen of Lesser April Jester moth (Stulte aprilis dies), collected in Oxford in 1951

The moth will exit the pupal case and, if necessary, will tunnel to the surface, squeezing out through the cracks in the pavement. It will unfurl its glorious, clear wings, displaying the red, blue, green and yellow stripes, on its back, for all to see. It will then fly off to find a mate, to ensure the next generation of this rarely seen insect.

Burrow of Lesser April Jester moth (Stulte aprilis dies) in pavement of Parks road, 1 April 1951

Unfortunately so many jester moths never make it out of their pupa, whether due to the required conditions never being met, or to not having enough energy to dig their way to the surface. If you wish to help, gently inserting and then removing small twigs between paving stones to loosen the soil can help to ease their paths.

The last know sightings in Oxfordshire occurred on Parks Road in Oxford on 1st April 1951. Please let us know if you catch sight of this moth, and even better please share any photos you may take either in the comments below, or via the Contact us page.

Insects Online

When the weather is chilly there aren’t many insects about, but we still have lots of online ‘Crunchy’ insect activities for you to try. We hope they will boost your insect expertise!

How to spot an insect

What makes an insect an insect? How to spot an insect is an introduction to insect anatomy: the body parts that make up an insect. Discover the key features entomologists use spot insects and how insects are different from some of their close relatives. You can then test yourself with our quick quiz!

Insect ID

Ever wondered what that insect is? Insect ID takes you into a deeper exploration of the ‘Big 5’ groups of insects in Britain:

  • beetles
  • bees, wasps & ants
  • butterflies & moths
  • true flies
  • true bugs.

Discover the differences between them, learn how to spot each type and put your skills to the test with our ID challenge.  

Know your bees

There is more to bees than hives and honey! Know your bees explores some of the rich variety of bees found in Britain. We’ve also included some tools to help you make your own observations of bees.

Looking for more?

Hummingbird hawkmoth, Macroglossum stellatarum. Image credit: Rodger Caseby

If you’d like to go a bit further and, as the weather gets a bit warmer, get outside and do some investigating of your own, why not try one of our inset investigation ideas:

  • Different flowers asks whether different types of flower attract different insects
  • Insect Pollination investigates the range of important insect pollinators (it’s not just bees!)
  • Time of day explores whether different insects visit flowers at different times of day

We would love to hear how you get on. Get in touch using the comments below or the Contact Us page.

CSI: Crime Scene Insects

How can insects help solve crimes? In this video, forensic entomologist Dr Amoret Whitaker discusses her work and how she came to work with some common flies that can provide important clues.

The blow flies that Dr Whitaker talks about are a family of flies (Diptera) called the Calliphoridae. They often have bodies with a metallic sheen and are also known as carrion flies, bluebottles and greenbottles. The fly pictured in the video is Cynomya mortuorum, known as the yellow-faced fly or sometimes, more gruesomely, as ‘the fly of the dead’.

Forensic entomology is just one way in which scientists work with insects. If you would like to know more about different entomologists and what they do, visit the People section of the blog.

The Natty Winter Gnat

There aren’t many insects out and about at this time of year but on a warmer day you may see clouds of winter gnats (Trichocera annulata and related species) ‘dancing’ in the sunlight.  

Trichocera sp. swarming © Tuomo Tuomikoski, CC BY-SA 4.0

What persuades these small flies to come out in the depths of winter? Well, the dancers are males hoping to attract females. It’s thought that gathering together in a group like this makes it easier for the females to spot them. The trouble is, each individual male then has to compete for her attention!

If you are out for a walk, it may seem that a group of gnats is following you around; that’s because they are! If you are the warmest thing around, they will stay near you and make the most of your body heat.

You don’t need to worry about being bitten: although these gnats look a bit like mosquitos, they are completely harmless. The adults aren’t interested in drinking your blood, they feed on nectar. The larvae can be found in leaf litter, feeding on fungi, leaf mould and other decaying matter.

You can find out more about Trichocera on the Bug Life website: https://www.buglife.org.uk/bugs/bug-directory/winter-gnat/

Red-Tailed Bumblebee

If you see a big jet-black bumblebee with a red tail in Britain, its probably the Red-tailed Bumblebee, Bombus lapidarius. If it has a scruffy white collar, then its a male.

The Red-tailed Bubmblebee has extended its range northwards in recent years and is now common throughout Britain. It can often be seen in parks and gardens. The workers have short tongues and forage on flowers like daisies and thistles which have a big area for them to land on and are made up of small florets, each with a little nectar. Leaving dandelions to grow in the spring helps provide food for these and other insects early on in the growing season.

Let dandelions grow in spring to help insects. Image credit: Pixabay / Claudiu Mladin CC0

The Queens nest under stones and so are sometimes disturbed when these are moved. If you find one like this, have a look without disturbing it then just put the stone back. They may also enter our homes through open windows in search of nesting sites.

The Red-shanked carder bee, Bombus ruderarius, can look similar but is much scarcer in the UK. While the Queens of B. ruderarius are smaller. the workers of the two species can be a similar size. You can tell the difference by looking at the back legs. B ruderarius has red pollen baskets on its otherwise black legs, whereas the leg hairs of B. lapidarius are all black.

Lincoln Kwong was one of the participants at our Summer school in August. He was so inspired by the HOPE collections team at the museum that he decided to start his own insect collection. One of his first specimens was a dead red-tailed bumblebee that he found in his garden. He preserved and pinned this and recorded the data following advice from James.

Bombus lapidarius. Image credit: Lincoln Kwong

Let us know if you have your own collection. You can get in touch using the CONTACT US page. We’d also love to see any pictures any would be happy to feature them in our PHOTO GALLERY!

Featured image credit: Gail Hampshire CC BY 2.0