18 September, 2008

'Little' Big Greasy's Big Day Out

'Little' Big Greasy's Big Day Out
For more than a week a male Big Greasy butterfly, Cressida cressida, has been patrolling a patch of our garden where there are some young Aristolochia vines. These vines are the host for a number of butterflies including the spectacular Cairns Birdwing.

When I wasn't watching he must have been visited by a girlfriend as eggs like this were laid on all the vines.

Yesterday one of the eggs hatched. The scale on the ruler is in centimetres. Today he was joined by another. The male is still flying circuits past these vines. Maybe he is keeping other butterflies from laying on 'his' vines. There are too many eggs for all the caterpillars to reach maturity so it will be interesting to see what happens. Related species are know to be cannibals.

This is one of the butterflies having a hard time because of the introduced Dutchman's Pipe Vine, Aristolochia elegans. The female will lay her eggs on this close relative of the host but the larvae hatch, begin feeding and die. At least this is a wide spread species with populations well away from human habitation. The Richmond Birdwing, Ornithoptera prianus pronomus, has suffered loss of habitat and the trials of the introduced garden plant killing its young.

The first specimens of this species collected for science were taken near Cooktown when Cook was forced to repair his 'Endeavour' there in 1770.

This is the same leaf as pictured at the top. Somehow I have reversed it. I'll keep you informed of progress. Below is a pupa which has over wintered. Hopefully I'll get a picture of the butterfly for you.
For more information on this beautiful butterfly have a look at http://www-staff.mcs.uts.edu.au/~don/larvae/papi/cressid.html


Junior Lepid said...

Yes, I hope you get a shot of an adult, Alan.

Your observation that Dutchman's Pipe is toxic to the larva of Cressida cressida is interesting.

According to Braby, this species use the flowers of A. elegans as a host food plant. If you are noticing mortality on this particular plant, I think you should probably report it to your local Entomological Society.

Alan Gillanders said...

Junior lepid, I do not have the Braby two volumes but reading between the lines of his field guide and what I have heard from others it is possible to raise C. cressida on A. elegans flowers but if the larvae are left to themselves they will eat the leaves and die. Around here in Yungaburra I have only seen the eggs laid on the leaves and not the flowers of the vine near the post office.