The
threat to the survival of butterflies is largely down
to loss of suitable habitat caused by changes in land
use over successive generations. By giving children first
hand experience of butterflies we can make them aware
of these causal effects as well as involving them in witnessing
the wonders of the life-cycle of such a splendid creature.
Insects have always been a source of wonder and great
interest to kids. Children of all abilities can possess
an extensive knowledge of particular ‘creepie-crawlies’.
Try do some planting with 7 year olds. While you are trying
to keep an eye on safety aspects (amongst other things)
they are busily spotting and pointing out every single
living thing that has escaped your notice. Enthusiasm
is boundless. Survival is the keyword!
The topic of Butterflies is often an area where, although
children are aware of them, their knowledge can very superficial.
It can provide an excellent starting point for work (and
play!) in many areas of the curriculum - science, art,
maths, design technology, English, and more.
Some schools do good work in establishing and maintaining
‘wild areas’ in their school grounds. However
a long term commitment and much work out of ‘contact’
hours is often necessary and not easily manageable for
busy teachers.
Breeding butterflies in the classroom on the other hand
is very possible. Once you get set-up you have a resource
that can be used every year.
What
you need:
- Flight cage
- Source of
butterfly eggs or larvae (caterpillars)
- Food source
for hungry caterpillars
Cage
If you are ‘handy’ a wooden framed
cage is a worthwhile investment of your time. Cover with
black netting (available from sewing shops/ department
stores). Ensure that one side is removable to give access
for feeding. A good tip is to make your flight cage a
suitable size to fit in a car to allow the ‘little
darlings’ to be taken home weekends and holidays.
An alternative structure can be made from
an empty plastic sweet jar (from your local sweet shop)
and the above mentioned black netting. Use a Stanley-type
knife to remove rectangular sections from two opposite
faces of the jar. Then glue or sellotape netting on the
outside of the two holes. This will hopefully keep your
caterpillars in while allowing good circulation to maintain
a healthy micro-climate in the ‘cage’. Keep
the ‘cage’ in an upside-down position –
unscrewable lid at the bottom, for easier removal of droppings
and old food (droppings fall to the bottom).
Tip:
The gauge of standard netting is too large for
the early stages of caterpillar development. They escape!
Enclose the ‘mini-cage’ with a sock made from
an old pair of tights and tie at the top until the caterpillars
put on some weight.
Considerations
Many
species of butterfly require a specific habitat in the
wild which they have adapted to over time. Release of
bred specimens will most probably not be successful for
those individuals. A great deal of valuable monitoring
of local butterfly populations, especially the rarer species,
can be undermined by such releases. What then are you
going to do with your adult butterflies?
The problem can be minimised by sticking to the more common
species – small tortoiseshells, peacocks, large whites.
Release of 20 to 30 individuals locally will have minimal
impact in that these species will disperse over a wider
area.
What
stage of the life cycle do you start with?
What came first – the butterfly or
the egg?
The caterpillar stage is probably the most straight forward
stage to start with. Many gardeners are more than willing
to supply you with large white caterpillars. Late Summer
is probably the likeliest time for ready availability.
Just ask! A more expensive route is to buy large white
pupae (chrysalids) from a supplier such as World
Wide Butterflies. These are available earlier in the
year. Large Whites overwinter as pupae, first emerging
as adults in May. Caterpillars collected in September
can be taken through to the pupal stage and then allowed
to hibernate in a cold location (attic, shed). The same
class of children can see these same individuals emerge
the following May.
Small tortoiseshell and peacock larvae are sometimes available
from gardens. They live in large colonies of perhaps 100
– 200 individuals. Removal of a small percentage
will not threaten the colony.
Caterpillar Food
Caterpillars, in common with children,
need a constant supply of fresh food. The maxim "You
gotta eat your greens" certainly holds here. Choose
your species carefully. Small tortoiseshells and peacocks
require a daily supply of fresh nettles. Large whites
require cruciferous plants – cabbage, Brussel sprouts
(good example to the children!), nasturtium, amongst others.
Cabbage produces droppings (called frass) which is quite
smelly. Nasturtium is easier on the nose.
Food
Tips:
- several
days supply of nettle can be kept in the fridge.
- food
plants must not be left standing in water in the cage
as the water content will be too high and result in
high mortality.
- grow
nettles/nasturtium in pots, but requires forward planning.
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