Insect super powers: dodging death

Being near the bottom of the food chain isn’t ideal.  Insects have many different predators including lots from the insect world itself and that’s before you’ve even started to take account of all the birds, fish, reptiles, amphibians and mammals that consider insects an important part of their diet.  So how do insects dodge death and defend themselves against predators?  Read on to find out about some cunning techniques and surprising solutions!

Chemical Warfare

Did you know that some species of ladybird have clever, and some rather disgusting, ways of deterring predators?  Not only do many species display the bright warning colours of red or yellow combined with black, but some can exude a stinky yellow liquid through their knees when in danger.  This is called reflex bleeding because the liquid is made from their blood.  You may have noticed it if you have picked up a ladybird and seen yellow spots of liquid on your hand. 

Other insects can squirt noxious fluids into the air when they feel threatened.  Wood Ants, for example, spray formic acid.  The incredible Bombardier Beetle (seen here on the right) can combine two different liquids stored in separate chambers in its abdomen to produce a boiling hot chemical that literally explodes from the beetle’s rear. I wouldn’t like to be on the receiving end of that!

Cloaks of Invisibility

For many insects, protection from predators is all about not being seen.  There are some amazing masters of disguise whose camouflage is so good we have trouble spotting them.  For example, many moths are almost invisible when resting in their preferred habitat such as on the bark of trees.

How many insects can you spot?

Another form of camouflage is to disguise yourself as an object of no importance, such as a twig.  When threatened, this beetle (Platyrhinous resinosis) rolls over, draws in its legs, lies very still and looks just like a bird poo!

Platyrhinous resinosis

Masters of Disguise

If you can’t blend in with your background, you could always be a master of mimicry and pretend to be something really scary! This Hornet Clearwing is not actually a hornet with a powerful sting. It’s a moth, but by mimicking the colours and form of the hornet it will manage to put off many a hungry bird!

Serious Weaponry

Some insects have formidable weapons that may serve to fend off rivals, help catch prey and deter predators.  Look at the ferocious jaws of the Stag Beetle or the sharp pincers, or forceps, at the rear end of the earwig.  They might make you think twice before tackling these guys! In fact, the jaws of the Stag Beetle are all show!  They are actually quite weak and may even prevent Stag Beetles from feeding in their adult form. The fact that they exist at all just shows how effective they are at warding off predators.

Let us know if you have a favourite story about how insects dodge death and survive in a world full of predators.

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?

Arctic Pollinator Watch

Become an arctic pollination investigator without even putting your coat on! Scientists investing pollinating insects in the arctic need your help. By spotting pollinators in images taken by remote cameras, you can help teach a computer system how to identify these insects which are vital to arctic ecosystems.

Bees, butterflies, beetles and many other insects are pollinators. Image credit – Image by Mabel Amber from Pixabay

Insects are important pollinators all over the world, including the arctic region around the North Pole. By moving pollen from flower to flower, insects enable new seeds and fruits to form. These seeds will grow to become the next generation of plants. Without pollinators, many species of plant would die out because there would be no young plants to replace the old ones.

The Department of Bioscience at Aarhus University in Denmark have set up time-lapse cameras at various arctic locations. For the past three years, these cameras have gathered thousands of pictures of flowers. It would take an enormously long time for humans to locate and identify pollinators in these pictures, so the researchers now want to train a computer to do it. A computer has already identified pictures that include flowers (although it may not always get tis right). The researchers need your help spotting any pollinators that may have visited the flowers in these pictures.

Become a ‘polliwatcher’ on the Pollinator watch website

You can join the project by visiting the Pollinator Watch pages of the Zooniverse website. You can then click ‘Learn more’ to read more about the project and the researchers, or ‘Get started’ to start hunting for pollinators. There is a short tutorial to help you learn how to spot the insects, and then you can hunt through as many pictures as you like.

You don’t need to register with the site to take part but if you want to, make sure that an adult gives permission. Signing in means you can keep up to date with the project and you will get credited if you find something special!

Don’t forget to let us know how you get on by sending us a message on the Contact Us page.

Make do and Mend!

The HOPE British insect collection includes specimens from the early 19th century to the present day.  This means that some are very old and delicate.  Of course, all of the insects are very delicate and easily damaged.  Just think about the width of the legs or antennae of some of the insects you have seen in your garden!  Not much more than a hair’s breadth!  It isn’t surprising then that some of the specimens are showing their age and some are damaged.

In this post, learn how Tom Greenway, Junior HOPE Collections Assistant, repairs the damage and what happens to the bits that can’t be stuck back on!

“It’s always sad to see a damaged specimen but with a little bit of patience, and a mix of PVA glue and distilled water, we can make repairs to get them looking like new again!” 

Tom Greenway, Junior HOPE Collections Assistant

It isn’t unusual for the abdomen to fall off, as you can see here! Watch this video to see how we repair specimens.

Sometimes specimens will build up verdigris; a bluish-green crust made by a chemical reaction between the old pin, the insect and oxygen. We use a small brush to lightly remove it. Pins sometimes become rusty or damaged need to be replaced.  For that job we use special stainless steel entomology pins.

Any parts that may have fallen off, but can’t be assigned to a particular specimen, are collected and stored in a gelatin capsule. This can be useful for any researchers looking to analyse DNA. The capsule gets pinned at the end of the specimen drawer so that it is kept with the correct species. 

People: Ellen & Frederick Hope

We step back in time to meet the two people who founded the original ‘bug and butterfly’ collection, Ellen Meredith and Frederick William Hope.

Frederick and Ellen were both born near the start of the 1800s. The two young people had a number of shared interests including collecting engravings and learning about nature. What fascinated them the most was entomology – the study of insects. This was to lead to a shared lifetime of learning about them.

Wytham Woods – a great place to look for insects. Image credit – Alan Wood / Wytham Great Wood CC BY-SA 2.0

Frederick had become fascinated by wildlife as a student at Christ Church College, Oxford. He had spent a lot of his spare time collecting insects at Shotover Wood, Port Meadow and Wytham Woods. These are still all good places to look for insects today. Ellen had not studied for a degree because at that time women were not allowed to go to university! She didn’t let that get in the way of pursuing her interest. She became as equally knowledgeable as Frederick, and was elected as the first female Fellow of the Royal Entomological Society in 1835.

“A life as the wife of a politician would have been a very dull one indeed.”

In 1833, Ellen had turned down a proposal of marriage from Benjamin Disraeli (who would later become Prime Minister) because “a life as the wife of a politician would have been a very dull one indeed”. Two years later she married Frederick and they set up home together at 37 Upper Seymour Street, Marylebone, in London.

With two avid insect collectors living in the same house, their home rapidly became a small museum! Frederick and Ellen opened their collection to the public on certain days, and it soon became a popular meeting place for entomologists and others interested in natural history. Many famous naturalists became regular visitors, including Charles Darwin.

The Museum of Natural History became the new home of the Hope Collection

As their collection expanded, they realised that it would eventually outgrow their home. They also wanted to find a way for more people to see and learn about the insects they had collected. In 1849 they offered their entire collection, known fondly as the ‘bug and butterfly’ collection to the University of Oxford. When the Museum of Natural History opened in 1860, it provided a home for the Hope collection, and we have been looking after it ever since.

Sadly, Frederick died in 1862 but Ellen continued to support the Museum as they had done together. She up a £10,000 trust fund to provide for the Keeper of the collection of engravings, the Hope Professor of Zoology, and for the curators of the insect collection, so they could look after and continue to add to it.

Ellen Hope continued to contribute to the collection after Frederick’s death.

Ellen remained actively involved in the Hope collection, donating both money and new insect specimens. Shortly before she died, in 1879, she wrote a stern letter to the university authorities opposing their plan to merge the position of Hope Professor with another job and reminding them that this would break the agreement they had made. She wanted to make sure that the Hope collection would be given the attention it deserved.

The Museum of Natural History will soon install a new Ellen Hope Gallery in the space next to the room that held the original collection. The gallery will look at habitat loss, changes in biodiversity, and the value of museum collections in understanding these changes and their impacts. The insects Ellen and Frederick collected all those years ago, and generations of scientists have added to, will now help us understand how to look after the natural world today and in the future.

If you live in or near Oxford and would like to look for insects in some of the same places Ellen and Frederick did, you could visit these places:

Please check the sites for opening times and rules before you visit.