Delightful Damselflies

One of the delights of summer is seeing slender bright blue damselflies flying near water. One of the most beautiful is the Azure damselfly, Coenagrion puella.

Dragonflies and damselflies make up the order of insects called the Odonata. Damselflies are members of in the sub-order Zygoptera, meaning “paired-wings”. Dragonflies are in the sub-order Anisoptera, meaning “unequal wings”.

You can tell the difference between damselflies and dragonflies because, in general, the body of damselflies is more slender and delicate compared to that of dragonflies. Damselfly eyes are separated on either side of the head, but dragonfly eyes are often so large they may touch. The forewings and hind wings of damselflies are the same shape, whereas the hindwings of dragonflies are broader than the forewings. Damselflies also tend to close their wings along their body when at rest but dragonflies hold their wings open. Damselflies are not as strong fliers than dragonflies and so may spend more time resting.

Newly-emerged adults are called ‘Tenerals’. They can appear very pale and may not have their mature colouration yet. You may have to look closely for any emerging markings or patterns to help identify it. Very mature adult damselflies can appear much darker.

The Azure Damselfly, Coenagrion puella, is found throughout England and Wales and in Southern Scotland near water, including garden ponds, in which the larvae develop. There is no pupa, instead, the adult develops inside the final larval stage and emerges directly from it. Adults fly between April and September, usually near water. They are about 3cm long and, as their name suggests, the males are banded with blue stripes on their black body, although the females are usually a bright green and black.

The male colouration looks similar to several other blue damselflies but can be distinguished by the pattern, especially on the second abdominal segment. You’ll have to look closely! Try taking a photo and zooming in.

Banding patterns in some similar blue damselflies

(a) C. puella has a U-shaped black mark on the upper side of this segment.

(b) In the Variable Damselfly, Coenagrion pulchellum, this ‘U’ has a ‘stem’ making it look more like a wine glass.

(c) The Common Blue Damselfly, Enallagma cyathigerum, has a marking shaped like the ‘spade’ on playing cards.

(d) In the Northern Damselfly, Coenagrion hastulatum, which is found in Northern Scotland, the ‘spade’ shape looks more like an arrow head.

(e) The mark on the Southern Damselfly,  Coenagrion mercuriale, found in Southern and South-western England and Wales, has ‘arms’ and is sometimes said to resemble a ballet dancer.

Have you seen an Azure Damselfly, or any other type? We would love to hear about it or see your pictures, of these or any other insects. You can get in touch using our Contact Us page.

If you enjoyed reading about these insects, you might like to try making your own dragonfly glider.

Let there be Light!

When is a worm not a worm?  When it’s a glow-worm… because a glow-worm is actually a beetle!

Male glow-worms look like typical beetles with wing cases (elytra) covering their second pair of wings, but the females are very different, having no wings and resembling beetle larvae.  It is the females who emit a greenish-orange glow from their back ends by a process called bioluminescence. Light is produced by energy released from chemical reactions occurring inside the glow-worm’s body.  In nature, bioluminescence occurs in many different types of organisms from bacteria to marine vertebrates and invertebrates.  It serves different purposes such as to warn or evade predators; lure or detect prey; or, in the case of the glow-worm, as a means of communication. The female glow-worms use the light to attract males.  Male glow-worms have large eyes with a high degree of sensitivity to light, so they are well adapted to being able to spot females in the dark. Once the glow-worms have mated, the females stop glowing and lay their eggs. If you are out for a night time walk in an area of grassland in June or July, you may be lucky enough to spot these amazing insects glowing in the dark! Glow-worms can be found in England (particularly in the South), but also in lowland Scotland and Wales.

Ferocious Predators

Glow-worm larva hunting snails. Image credit: CC-BY-SA-4.0, Hans Hillewaert

It is not only the female glow-worms who can glow, however.  The larvae are also able to flash a light on and off and it is thought that this is to deter predators or to help with their night time hunting. Glow-worm larvae are ferocious hunters of slugs and snails!  They have formidable mandibles and inject toxins into their prey which paralyses and liquefies them.  The toxin can take a while to take effect so the larva may ride around on the shell of the snail, waiting for it to die! The larval stage of the glow-worm lasts for between 2 and 3 years.  Winters, when prey is scarce, are spent in a state of torpor under logs and stones, or buried in the ground. 

The Race is On!

Once the larvae have pupated, the glow-worms need to mate as quickly as possible.  They do not eat as adults and only have enough stored energy from their larval stage to survive for about 10 days before starving to death.  Hopefully with a bright lantern to attract the males, the females will mate successfully and have her eggs fertilised before dying.   

Have you seen a glow-worm recently?  We would love to hear about it.  Let us know in the comments below or via the contact us section of the blog.

Queen Bees and Royal Jelly

As Britain celebrates the Platinum Jubilee of Elizabeth II, HOPE For the Future Community Engagement Officer, Hayleigh Jutson takes a look at the queen at the heart of every honey bee hive and find out why royal jelly is crucial to her reign.

Honey bees on honeycomb.

Social bees are species that live together in groups called colonies. These colonies are very structured, with different bees having specific roles. Social bees include honey bees and many species of bumblebee. A queen bee is the only bee in a hive of social bees that produces eggs. Larvae will hatch from these eggs and develop into adult bees, so the queen bee will be the mother of most of the bees in the hive.

A queen bee in a hive. Image credit: OUMNH

The queen bee governs the colony. Most of the other bees are female worker bees and nurse bees. Workers are responsible for foraging, caring for the nest looking after the rest of the colony. Nurse bees raise the queen’s offspring, who are also their sisters. All these female bees develop from fertilised eggs. Later in the year, the queen starts to produce some male bees called drones. These drones develop from unfertilised eggs. Their only job is to mate with queen bees. They don’t even feed themselves! Instead, the female workers have to feed them.

Queen cells containing larvae surrounded by royal Jelly. Image credit: Waugsberg CC BY-SA 3.0

Towards the end of summer, as well as producing unfertilised males eggs, the queen bee also lays some eggs in specially constructed queen cells. What makes these specially chosen individuals grow-up to be queen is a substance called ‘royal jelly’. This is a milky secretion that comes from glands within the heads of nurse honeybees. While all the bee larvae receive some royal jelly in the first few days after hatching, the one selected to be queens are fed large amounts of it from their larval stage to adulthood. A special protein in the Royal Jelly called ‘royalactin’ enables the larvae to develop ovaries so they can produce eggs and, perhaps become queen of their own hive.

Queen Bumblebees

Queen bumblebees overwinter underground, and are usually the first to emerge in early spring. When the queen bees awake from their long slumber, they are extremely hungry and in a hurry to start a new colony of their own. The queen begins by feeding on early-blooming wildflowers and tree blossoms, which provide her with all the nutrition she needs with protein-rich pollen, and high-energy nectar.

Queen Tree Bumblebee. Image Credit: Hayleigh Jutson

Once she has filled up on all the nutrients she needs, the queen will then find a suitable nest site. Different species choose different sites. She will collect a ball of pollen and lay her first batch of eggs inside it. Bumblees incubate their eggs, like birds do, and even have a bald-patch on their abdomens, to ensure suitable distribution of their body heat over their eggs. The queen builds a store of honey to feed from, while she does this. When they hatch, the larvae eat their way through the pollen and the queen continues to care for them, until they are fully-grown adults.

If you are interested in bees, have a look at our post about the red-tailed mason bee. She is a solitary bee who chooses a very unusual place to lay her eggs.

Hayleigh is working with the HOPE project team to develop and deliver a programme for working with intergenerational groups in the community and making the Museum an Age Friendly space for older people. She wants  “museums to be a space for all to enjoy and develop their sense of wonder and imagination, no matter what age they are”.


Fabulous Fig Wasps

Many insects are important pollinators helping plants to make seeds from which new plants can grow. One of these is the fabulous fig wasp. In this video fig wasp researcher Sotiria Boutsi explains the amazing life cycle of the fig wasp, and why without it we wouldn’t have any figs!

Sotiria Boutsi shares her fascination with fig wasps

Sotiria shared her interest in fig wasps with Crunchy on the outside while she was a Professional Intern in Public Engagement at the Museum of Natural History. She has a Master’s degree in Conservation Biology and is currently researching for a PHD at Harper Adams University on using genetic information to study how different species of fig wasp are related to each other.

You can find out about other amazing insects in the Insects section of the blog.

Update: So, are there wasps in figs we eat?

Sotiria’s video sparked some debate on social media about whether there are wasps in the figs we eat. This is a complicated subject, but the short answer is ‘no’. Many figs that are produced for sale in supermarkets and greengrocer’s shops are ripened without the need for them to be pollinated by insects. Some figs produced for sale are pollinated by fig wasps, but the fig produces a chemical that dissolves the wasps.

So, any crunchy bits inside a fig are seeds, not wasps!

Header image: Fig wasps, Philocaenus rotundus, on a fig. Alan Manson CC BY 4.0

The Marvellous Maybug

As the month of April fades into May a certain beetle can be found flying noisily about its business. Cockchafers, often called Maybugs, are relatively large members of the Scarab beetle family. There are three different species of Cockchafer found in Europe;

  • The common cockchafer, Melolontha melolontha
  • The forest cockchafer, Melolontha hippocastani
  • The large cockchafer, Melolontha pectoralis

Cockchafers spend most of their lives, 3 to 4 years, as larva, living underground, munching away at the roots of plants. In large numbers they can become pests, doing significant damage to crops.

It is as adults that they emerge above ground, flying around for roughly 5 to 6 week looking for a mate and feeding on the leaves of trees. They can usually be spotted making their noisy flight at dusk on warm evenings. You may even find them flying into and around your outside lights.

Common Cockchafer (Melolontha melolontha) © OUMNH

They are around 3cm long, with reddish brown wing cases and distinctive fan shaped antennae. Despite their intimidating size and noisy flight, they are actually harmless to humans. I once had one fly in the house and land on my big toe, waking me up from a nap!

Pesticides used farming in the mid-1900s brought them to the brink of extinction in the UK. However, changes in farming practises and pesticide use has allowed them to make a comeback. They can now be found across England, are particularly common in the south of England and the Midlands. They are much rarer in Scotland.

Do you know of any other insects that are considered pests by farmers? Let us know in the comments below or via the contact us section of the blog.

Your questions answered: ‘Which is the most successful species of ant?’

Noah contacted us recently with an intriguing question: ‘What is the most successful species of ant?’. It really got us thinking! Insects are a very successful group of animals, and ants are very successful insects, but how could we decide which is the most successful?

There might be different ways we might measure success. It is the most numerous ant? Or the group with the most species? It might be the species that’s most widely spread across the globe? Perhaps it’s the longest-lived, or the largest?

Successful ants

Ants are a very successful group of insects. The biologist E.O. Wilson (who died recently) estimated that there may be a million ants for every human being, but the truth is that we don’t really know. Although they are small, there are so many of them that they may make up a quarter of the mass of all land animals!

Scientists think that ants probably evolved from a type of wasp 168 million years ago. They became really successful after flowering plants evolved about 100 million years ago. We know this because ants appear much more often in the fossil record, and we start to find many more species . One of the oldest fossil ants is Sphecomyrma, found trapped in 99 million year old amber from Myanmar.

Micrograph of a fossil ant trapped in amber. Species undetermined. 50 million years old.
Fossil Ant trapped in Amber. Image Credit: OUMNH

Features that have helped ants to become so successful include:

  • Their social nature – ants in a nest are good at cooperating.
  • They modify habitats – most animals can only survive in certain conditions but ant colonies can change their surroundings to suit them.
  • Ants can use a wide range of food sources. Some species even farm – growing fungi or ‘milking’ aphids for food.
  • Defence – ants are really good at defending themselves and each other. They are strong, have biting mouthparts and produce acid. The origin of the word ‘ant’ means ‘biter’.
  • Some species form supercolonies – huge nests containing several queen ants. This level of cooperation and organisation help some ant species to be mega-successful.
The ability of ants to cooperate helps make them successful.

Which ants are most successful?

So, ants are very successful as a group of insects. Here are some examples of ant species that might be the most successful:

Most numerous: Difficult to say, but perhaps the Argentine ant Linepithema humile.

Widest distribution: Several contenders for this, but perhaps the fire ant Solenopsis invicta.

Most different species: The genus Pheidole with over 1,000 described species.

Largest: The fossil giant ant Titanomyrma gigantuem was the largest ant to have lived. The queens were 6cm long with a wingspan of 15cm.That’s about the same size as a hummingbird!

Longest lived: We think oldest individual ant on record in a laboratory was a queen of the species Pogonomyrmex owyheei which lived to be 30 years old. Colonies of ants can survive for centuries in nature, continuing through many generations of ants.

The fossil giant ant Titanomyrma lubei, with a hummingbird for comparison.
Image Credit: Simon Fraser University CC BY 2.0

The fact is, however, that every species has most of the characteristics that make all ants successful, so perhaps the most common British ant, the Common Black Ant, Lasius niger, is as good a candidate for most successful as any? It’s also worth remembering that entomologists think we have only described about two thirds of all ant species – so there are many more left to discover!

We hope that answers Noah’s question. If you have a question about insects or the museum you’d like to ask us, just write it in the comments or send us a message using the Contact Us page.