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This page contains pictures and information about Common Australian Crow Butterflies in
the Brisbane area, Queensland, Australia.
- Wingspan 90mm, male and female
Common Australian Crow Butterflies are also called Oleander Crow.
The above picture shows a male, notice his narrow opaque make on the forewing, which
release perfume to attach the female. This is the most common butterfly in Brisbane. In summer, we see them
everyday, everywhere and even in the city. We sometimes see them in winter, although not so often.
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- Female
Male
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- Common Australian Crow
Butterflies are
shiny black in colour with scattered white marks on their wings. They
reflect the dark blue colour under sun light. Male and
female look similar except male has the narrow opaque make on the
forewing.
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- At night the butterflies aggregate together in sheltered area. In winter
their aggregation even be in very large number. They usually rest within a
few meter above ground on trees.
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- The Crow butterflies have the weak sailing flight, usually a few meters
above the ground. They feed on a wide range of flowers,
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Butterfly to find a Mate
- Male butterflies are believed to look for their mate by eye-sight. Some
species, such as the Australian Crow and
Orchard Swallowtail,
patrol the field in search of females. Some species, like the Common Eggfly, take up and wait in some good
positions, such as the opening and clearings where the females will pass by.
Some other species, e.g. the Glasswing Butterfly found gathering around hill tops.
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- However, the butterflies vision may not be very acute as sometimes they
may made mistakes. They may approach same sex or even other species
butterflies. So the male will also recognize the sexual behaviour patterns
of the female.
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- The male Australian Crow fluttering above the female.
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- Once the male recognizes a female, he will stimulate her sexually so
that mating can take place.
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- In Australian Crow the male has the scent-glands
on the front wings and end of his abdomen. He will flutter above the female to diffuse his perfume
around the female. If he successful, she will settle and mating can take
place.
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- After mating, female butterfly will look for their caterpillars' host
plants, lay eggs and start the new life
cycle.
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Butterfly Reproduction Cycle
- Several generations completed each year, with butterflies most abundant
immediately after wet season.
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- Finding mate and female laying eggs on host plant
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- Egg on Monkey Rope leaves, length 2mm
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- Early instars, body length 10mm
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- Mid instars, body length 40mm
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- The butterflies also lay eggs on oleander Nerium sp. So the
butterflies are also called Oleander Crow.
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- Late instars, body length 50mm
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- The above pictures show the caterpillars feeding on oleander leaf
(first picture) and Monkey Rope leaf (second picture) freely during the day,
without worrying about predators. The caterpillar feed on those
plants which are poisonous to birds and mammals. The caterpillar somehow can tolerate the poison
and store them in their body. Both the caterpillar and adult butterfly are
then poisonous. Birds and other predators will avoid them.
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- The caterpillars have four
pairs of filaments on their body. They have narrow black and white bands with some orange colour.
This colour pattern is a warning sign to the predators, such as birds, that
“I am poisonous, don’t eat me.” When disturbed, the caterpillar
rolls-up part of its body with the head in the center
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- Pupa, length 25mm
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- Crow caterpillars pupate on food plants or other plants near the food
plants. In early stage, the Crow Butterfly pupa is metallic brown in colour
with silvery patterns.
Their pupa usually be found underneath a leaf.
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- About two weeks later, just before the adult
emerges, the black and write patterns can be seen under the transparent pupa
skin. .
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- Just emerge
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- It usually takes about two weeks time in summer for the pupa stage. The
above picture show the Crow just hatched from its pupa.
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- The Crow caterpillars and butterflies store the poison from their food
plants in their body to against their predators. However, they are not free
from natural enemy. We had raised some Common Australian Crows from
caterpillars. We found that
some of the caterpillars were parasitised by the
Tachinid Flies.
- Monkey Rope, Strawpod, Silkpod Vine - Common Australian Crow's host plant
- Parsonsia
straminea
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- The butterflies lay eggs on vine plants Monkey Rope Parsonsia
stramine, which is common in Brisbane bushland. The plant is a climbing woody vine holding on trees. Leaves are in
opposite pairs. There will be the small pale yellowish-pink flowers on early
summer. Seed pod can be seen in late summer. When the seed pod opens, there
are seeds with long white hair.
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- Reference:
- 1. Insects
of Australia, CSIRO, Division of Entomology, Melbourne University
Press, 2nd Edition 1991, p897.
- 2. Insects of Australia and New Zealand - R. J. Tillyard, Angus
& Robertson, Ltd, Sydney, 1926, p461.
- 3. Create
More Butterflies - by Frank Jordan and Helen Schwencke,
Earthling Enterprises, 2005, p14.
- 4. The
Complete Field Guide to Butterflies of Australia - Michael F Braby,
Australian National University, CSIRO 2004, p196.
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