Download Meeting Stag Beetles

Meeting
Stag Beetles
(Key Stage 3)
Deborah Harvey
The stag beetle’s life cycle
The stag beetle, Lucanus cervus, is Britain’s largest beetle. It is known as a stag beetle
or deer 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, flying 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 larva (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.
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Male stag beetle
The fully grown male stag beetle flies in
the evening, looking for a mate. It is up to
75mm long including its antlers. The antlers
are used for display, fighting 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.
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How do we know the stag beetle is an insect?
Like all insects 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 fighting 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 fine, veined pair underneath
which look like very large fly wings. When the stag beetle flies it holds the wing cases up
and unfolds the soft wings underneath. It flies upright with its large black wing cases held
behind it. It is also very noisy.
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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.
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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.
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Stagbeetle Friendly Gardening
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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 animals 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 influence 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/files/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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Royal Holloway, University of London
Egham, Surrey, TW20 0EX
T: 01784 434455
www.rhul.ac.uk
5539 06/09