Meeting Stag (Key Stage 3)

Deborah Harvey The stag ’s life cycle The stag beetle, , is Britain’s largest beetle. It is known as a stag beetle or beetle in many other European countries because of the shape of the male’s mandibles. In England, the beetle only lives in the south of the country. Many people have seen the male, with his large antlers, fl ying around on warm summer evenings looking for a mate. Stag beetles mainly live in the towns and are far less common in woods and parkland: 98% of all records from a 1998 national survey came from urban areas.

The adult stag beetle only lives for a few weeks then dies; it is the reproductive stage of a very long life cycle.

Stag beetle eggs The eggs are small (about 3mm long) and creamy coloured. The female lays them in the soil near rotting wood. After a few weeks they become rounder and paler. When the young larvae hatch out, they are completely white. The head goes orange over the next 24 hours.

Stag beetle (or grub) The stag beetle larva is cream, with an orange head, orange legs, and small brown antlers. It lives in rotten wood that it eats. It takes up to 6 years to reach full size (approx. 8 cm), shedding its skin 5 times in the process.

Pupa After 6 years, the larva leaves the wood and makes a cocoon in the soil. Next it turns into a pupa. This stage happens in late summer or autumn and lasts a few weeks.

Next the fully grown beetle leaves the cocoon but it stays under the ground until the next summer. This photo shows a male pupa with large antlers on top, and a female at the bottom.

1 Male stag beetle The fully grown male stag beetle fl ies in the evening, looking for a mate. It is up to 75mm long including its antlers. The antlers are used for display, fi ghting and holding the female still when mating. It does not need to eat, but it may feed on sap.

Female stag beetle The female stag beetle is smaller than the male (up to 55mm). She is often seen on the ground looking for somewhere to lay her eggs. She lays them in or near rotten wood then dies shortly afterwards.

2 How do we know the stag beetle is an ? Like all the adult stag beetle has three body parts: a head, thorax, and abdomen. It is covered with a tough cuticle, known as the exoskeleton, which is made of chitin - this protects the beetle and gives it support. It also means that the beetle cannot grow.

The head of the male has enlarged jaws or mandibles. These are used for fi ghting with other males, for attracting a mate, and for holding the mate still during mating. The stag beetle also uses his jaws to protect himself if he feels threatened. But his mandibles are very big compared to his head and the muscles that move them move them relatively small so he can’t bite very hard. The female with her tiny mandibles can bite much harder.

The thorax is joined on to the head and has the three pairs of legs attached. All insects have 3 pairs of legs joined to the thorax. At the end of their legs, stag beetles have little hooks to help them grip on to things.

Below the thorax is the abdomen. In the female the eggs will be stored here before they are laid. The stag beetle has two pairs of wings, like all insects. The top pair, also called elytra or wing cases, is very hard and shiny. These cover a fi ne, veined pair underneath which look like very large fl y wings. When the stag beetle fl ies it holds the wing cases up and unfolds the soft wings underneath. It fl ies upright with its large black wing cases held behind it. It is also very noisy.

3 Distribution of Stag Beetles in the United Kingdom

The map above shows the distribution of stag beetles in the United Kingdom. It was plotted following the National Survey of stag beetles in 1998, run by the Peoples’ Trust for Endangered Species. This map shows that most stag beetles are found in the South Eastern corner of England.

If you look more carefully it shows that there are three main areas in the South East: the Ipswich area, the Southampton and New Forest area, and the London area.

Reasons why stag beetles do not appear anywhere else are put down to climate and soil type, however nobody is really sure. And why is there a single record in North Wales? Perhaps it hitched a lift on a lorry!

A distribution map plotted in the 1960’s showed the distribution to be slightly wider than this – stag beetles appear to be losing their place in England. There are no stag beetles in either the North of England or Ireland.

4 Making a safe habitat for the stag beetle Late in the summer the female stag beetle buries herself under the ground near some rotten wood and lays her eggs. So how can you encourage stag beetles to breed?

You can… • leave any old tree stumps in the ground

• leave wood piles in your garden

• or build a special wood pile for the stag beetles. You can do this by digging a hole about 60cm deep, and putting wood, or rotting wood, into it so that the wood sticks up out of the ground. Then you just leave it alone and hopefully stag beetles will use it!

Once you’ve built your log pile try not to disturb it, and encourage your friends and relatives to leave wood and woodpiles in their gardens.

5 Stagbeetle Friendly Gardening

6 Guidance for teachers This resource is intended for use by children in years 7 through 9, but could easily be adapted for children of any age. It can be used in conjunction with our other resource packs – Insect Restaurants, 3D Bug Art, and Meeting Stag Beetles (Key Stage 2).

National Curriculum links Science, Life processes and living things, section 5 Living things in their environment – learning that habitats support a diversity of plants and that are interdependent, learning about how organisms are adapted to survive seasonal changes in their environment and about how living things and the environment can be protected.

Geography, Key concepts, Environmental interaction and sustainable development, understanding that the physical and human dimensions of the environment are interrelated and together infl uence environmental change.

Ideas for further work http://www.stagbeetlehelpline.co.uk gives lots of information on stag beetles, including instructions on “Burying a bucket for beetles”. This is a way to create a suitable habitat for stag beetles on a small scale, developed by Deborah Harvey at Royal Holloway, funded by the People’s Trust for Endangered Species. http://www.waddesdon.org.uk/explorer_trail/fi les/teachers%20science%20pack. pdf shows how to build a “bug hotel” to attract a wide variety of insects to a garden. http://www.geographyteachingtoday.org.uk/curriculum-making/teaching-ideas/ minibeasts/ illustrates how to use studies of minibeasts on school grounds within the Key Stage 3 Geography curriculum, with a scheme of work that includes data collection, mapping, and data analysis. http://ptes.org/ gives you more information about the People’s Trust for Endangered Species, the organisation that funded much of Royal Holloway’s research into stag beetles. There are some pages for kids.

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T: www.rhul.ac.uk Egham, Surrey, TW20 0EX Egham, Surrey, Royal Holloway, University of London University of Royal Holloway,