Where have
all the butterflies gone?
Nectar Plants
and Food Plants
Butterflies depend on
their habitats to survive. Plants are very important to
butterflies. They need two types of plants. They need flowering
plants, called nectar plants, that produce
nectar to keep them alive and they also need plants on which
the female can lay her eggs. These are called
food plants.
In the picture you can see an
Australian Painted Lady on an everlasting daisy
nectar plant. It is using its proboscis, which is
like a straw, to drink
the nectar. |
Original image: 'untitled' by:
Pierre Pouliquin
www.flickr.com/photos/28442702@N00/73103388 |
|
Only the
Right Plant Will Do
Butterflies will only lay their eggs on plants that their
larvae (caterpillars) like to eat. Different butterflies need
different plants and some of these plants are very hard to find.
|
Original image: 'silos'
by: Brian Yap
www.flickr.com/photos/30265340@N00/429441257
|
Loss of
Food Plants
In the
past, there used to be a lot more food plants
for butterflies. Nowadays the land on which
many of these food plants used to grow has
been cleared and is being used for other things
such as housing, growing crops and gazing sheep
and cattle. The butterflies have moved away.
In
the picture you can see some land that has been
cleared of most of its trees and native plants
and is now being used to grow crops |
|
Effects
of Insecticides
Some farmers
grow non-native grasses on their paddocks and use
fertilisers to encourage them to grow. This kills
the native grasses, which support butterflies.
Some farmers also use insecticides to kill
insect pests that might harm their crops. These
insecticides also kill butterflies. |
|
Different Types
of Gardens
Another reason
why there are fewer butterflies in the city could be that people
don't have as many nectar producing flowers in their
gardens as they used to. Nowadays many people prefer ornamental trees, lawn and paving,
because they don't have much time or because
they don't have room in their backyards for creating
the sort of gardens that butterflies love. Unfortunately,
too, some of the larva food
plants are considered to be weeds, so people get rid
of them, leaving butterflies with fewer places to lay
their eggs.
In the picture
you can see a butterfly-friendly garden. |
Original image: 'Garden' by
Edgeplot
www.flickr.com/photos/45789087@N00/63450609 |
Bushfires
Butterflies
are also threatened by bushfires and winter
burning of bushland to reduce fire risk in
summer. Winter burning kills butterfly eggs,
larvae and pupae.
Climate Change
Climate
change may also be having an effect on butterfly
numbers. Scientist who have researched the
problem are saying that butterflies are moving
away from where it's hot. Monash biologist
Dr Paul Sunnucks says that "They are trying
to get to where it's cooler. Just a couple of
degrees can make the difference between life and
death." |
 |
Some Good News
Fortunately, our national parks and wildlife
reserves are a safe haven for butterflies.
They
provide nectar plants and food plants
for many of our butterflies and their larvae. We
too can help by finding out which nectar plants
and food plants will attract butterflies to
our backyards and create
butterfly
gardens. We can also try to protect butterfly
habitats on private land, where possible.
The picture on the left, taken by the
author, shows Morialta Conservation Park,
which is a favourite spot for butterflies. |
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