chafers

During the summer you may notice large beetles flying around in gardens and other green spaces. These insects are called ‘chafers’. While they may look similar, there are in fact several different species all known by this common name.

The name chafer comes from the Old English word for beetle, ceafor. It is similar to the modern German word for beetle, käfer. So, ‘chafer’ really just means ‘beetle’ but in English it came to be used for beetles that were particularly noticeable. Chafers got themselves noticed because they are large, the adults can fly and often emerge in large numbers at the same time of year, sometimes making a buzzing noise as they fly. They are attracted to lights, so often fly in open windows, then bump around the room trying to get out. Farmers and gardeners often think of them as pests because they can damage plants.

Chafers all have a similar life cycle. The larvae live in the soil or dead wood, often for several years. They are sometimes thought of as pests because they may feed on the roots and other parts of plants, but they are important recyclers, feeding on dead, decaying material and helping to return the nutrients it contains back into the soil. The larvae then pupate and survive the cold winter months in this form. The adults emerge in late spring, or summer, depending on the species. It may seem that large numbers of beetles have suddenly appeared out of nowhere, but in fact these adults have just emerged at the same time. The adult beetles mate and lay eggs which will become the next generation of larvae.

Cockchafer, Melolontha melolonta

The largest of the British chafers is the cockchafer (Melolontha melolontha). The adults emerge in late April or May, giving it another common name, the ‘Maybug’. They fly in a wobbly way and make a buzzing noise. This can make them seem a bit alarming but they are completely harmless to humans.

Cockchafers were once a huge agricultural pest and could emerge in such numbers that people were encouraged to eat them! A French recipe for cockchafer soup was published in the 1800s (https://en.wikipedia.org/wiki/Cockchafer_soup) and in the 1920s, German children were reportedly eating sugar coated cockchafers.

Pesticides brought this marvellous beetle to the brink of extinction in the UK during the last century. Now changes in agriculture and pesticide use mean that cockchafers are making a comeback and they can be found across England, although they still rarer in Scotland. The nationally much rarer Northern Cockchafer (Melolontha hippocastani) is found in Scotland, Northern England and Ireland.

The Summer Chafer (Amphimallon soltitiatis) looks a bit like the cockchafer, but is smaller, at about 20mm, and had a rounded, rather than pointed tail end . Traditionally, this beetle is associated with the Summer Solstice, or longest day of the year, because the adults often emerge in the second half of June. In fact, the Summer Chafer can be found all over Britain in June and July. Kate and Susie found lots of Summer Chafers on a visit to Orchard Meadow Primary School in Oxford on 23 June this year and have seen it in the grounds of several other schools we have visited.

Another similar beetle is the Welsh Chafer Hoplia philanthus which, despite its name, is not restricted to Wales, but also found in Southern England and the Midlands. It is smaller and less ‘hairy’ than the other chafers and can be recognised by the single large ‘claws’ on the end of its legs.

Welsh Chafer, Hoplia philanthus. Image Credit: Neil Stanworth

Eleanor and her father kindly sent us this picture of a Welsh Chafer they caught in their garden in the Midlands recently using a pitfall trap they made after watching Kate’s video from a few weeks ago. We’d love to see pictures of beetles and other insects you have found.

Some chafers are a striking green colour. One of these is the Rose Chafer (Cetonia aurata) which flies between May and October. Gardeners may consider it as a pest, particularly if they grow roses, because the beetles feed on their plants but, like the other chafers, these beetles are also important recyclers.

Noble Chafer, Gnorimus nobilis. Image credit: Flickr/Gail Hampshire CC BY 2.0

Another green chafer is the Noble Chafer (Gnorimus nobilis). You can tell the two apart because the Rose Chafer has smooth wing cases but the Noble Chafer has wrinkled ones and is metallic green with white speckles. While adult Noble Chafers feed on plants like hogweed, the larvae live in the decaying wood of old fruit trees. Because of this, the Noble Chafer is found in traditional orchards. As these have disappeared, so has this beautiful beetle which is now rare and a priority species under the UK biodiversity framework.

So, look out for chafers this summer and send us pictures of the ones you find. You may even come across one that’s quite rare!

The Dark Edged Bee-Fly

The Dark edged bee-fly, Bombylius major, is one of the most conspicuous insects to emerge in early spring because of it’s large size and ability to hover in mid air. It is the most common species of Bee-fly in the UK and can be seen in woodland, heathlands, grasslands and gardens from February to June. It has several other common names known as the ‘dark bordered beefly’ or ‘large beefly’. They get these names from their large size and from the dark wavy leading edge of their wings.

Dark edged bee-fly, Bobylius major. Image credit – Flickr / Jean-Marie Hamon, CC BY-SA 3.0

So, is it a bee or a fly? The single pair of wings tells us that this is a fly. A bee would have two pairs of wings. Why would a fly evolve to look like a bee? We think this is to trick predators into thinking it is more dangerous than it is. It certainly works with humans: many people think that the beefly has a large ‘sting’ at the front. In fact, this is just part the fly’s mouth and is quite harmless. The proboscis is adapted to drink the nectar from a wide variety of early-flowering plants. These include primrose, bugle, blackthorn, and cherry blossom. Because they transfer pollen from flower to flower, they are important pollinators in the spring.

Bee-fly feeding on nectar. You can see pollen grains on its legs and body. Image credit – Flickr / Robert Ault, CC BY-SA 2.0

Bee-flies may be harmless to humans but their life cycle is a bit grisly! Females lay their eggs in the underground nests of solitary mining bee nests such as Clarke’s Mining Bee (Andrena clarkella), the Early mining bee (Andrena haemarrohoa), and the Tawny mining bee (Andrena fulva). They collect sand or dust at the end of their abdomens. This sticks to their eggs, making them heavier. It may also help camouflage them. They then flick their eggs into the nest burrows of the bees. Once the eggs hatch, the bee-fly larvae crawl further down the burrows and wait for the bee larvae to grow until they are near full size. The bee-fly larvae then begin to feed on the mining bee larvae, drinking their body fluids and gradually eating them alive. When they have finished feeding, the bee-fly larvae then pupate and overwinter inside the burrow. The next generation of adult bee-flies then emerges from the burrows the following spring.

The Twany mining bee, Andrena fulva. Bee-fly larvae feed on its larvae. Image credit – Flickr / Line Sabroe, CC BY 2.0

You might think that means that bee-flies are bad for other bee species, but this is relationship evolved a long time ago and is part of the complex interaction between living things that exists in all ecosystems. Bee flies do feed on individual mining bees, but there is no evidence that they are harmful to bee populations.

If you spot a bee-fly this spring or summer, you can add your sighting to the national database by completing a simple online form on the Bee-fly Watch website. Why not let us know too? You could even take a picture or draw a picture. Who will spot the first bee-fly of 2021?

Butterfly Origami

Have a go at making an origami butterfly. Origami is the art of folding paper into shapes and decorations, that originated in Japan. All you need to make this origami butterfly is a square piece of paper and a spare few minutes:

Here are written instructions for making the origami butterfly, in addition to the video:

  1. Take a square piece of paper. Fold it diagonally, press along the fold, and unfold. Repeat the other way.
  2. Turn the piece of paper over. Fold the bottom edge to the top edge, press along the fold, and unfold. Fold the left edge to the right edge, press along the fold, and unfold.
  3. Fold the left edge to the right edge, allowing the other edges to fold inward along the creases. This will form a triangle shape.
  4. Fold the top layer from both bottom corners of the triangle towards the top corner, but each slightly to either side of that top corner. Press along the creases.
  5. Fold the bottom layer from the top of the triangle towards the bottom flat edge, so that it overlaps a little, and fold it over. Press carefully along the crease, as the bottom “wings” will be drawn up.
  6. Press along the middle crease to help keep the fold over in place.

We would love to see pictures of your creations, please do share them with us.

Welcome to Crunchy on the Outside!

Crunchy on the outside is a new blog for and by young entomologists.

Interested in insects? Perhaps you saw something we posted online, came to the museum, or maybe we visited you at school for an Insect Discovery Day. However you heard of us, if you’re interested in insects this is the place for you!

We’ll be sharing news about insects and the natural world, people who work insects and help to protect them, what goes on at the museum, and new things for you to make and do. Look out for:

  • A peek behind the scenes at the museum
  • Insect related things to make and do
  • Info about people who work with insects, both past and present
  • Cool facts and stories about the amazing insects we can find in this country
  • A chance to have your say regarding what is in this blog and the museum
  • First dibs on related events

Crunchy on the outside is your opportunity to tell us what you would like from the museum, share your ideas and to get involved. We’d love to hear your ideas so please get in touch using the CONTACT US page if there is something you’d like to see.

Crunchy on the outside is part of the HOPE for the Future project at Oxford University Museum of Natural History. The project is funded by the National Lottery Heritage Fund.