canberrabirds

Entomology Corner - bugs and sex

To: <>, "Geoffrey Dabb " <>
Subject: Entomology Corner - bugs and sex
From: "Harriet Susan Searcy" <>
Date: Mon, 28 Mar 2011 13:56:07 +1100

I think this might be the same wasp that has been hanging around my flowering oregano (in Braidwood) – the photos show the same wonderful blue sheen to its wings.  More importantly – does it sting, apart from looking beautiful and sinister?   I’d be interested to know what its range is because I’ve never seen any in Melbourne/Victoria.

 

Harriet Searcy.

 

From: Geoffrey Dabb [
Sent: Friday, 25 March 2011 12:33 PM
To:
Subject: FW: [canberrabirds] Entomology Corner - bugs and sex

 

Thanks John.  Coming at it from the viewpoint of the orchid, the behaviour is mentioned in the useful ‘Wildflowers of the Bush Capital’, 1993, Ian Fraser and Margaret McJannett, page 86, in relation to Caladenia tentaculata the Green-comb Spider Orchid, the only Spider Orchid found in Canberra Nature Park.   If you want to see it, it seems September would be the time, the ‘peak flowering month’.

 

So what do these wasps do the rest of the time?  Maybe hang out around REAL pheremones?  Another thing is hang out around the abundant wild fennel, a great insect attracter.  I remember now that I asked about them about 12 months ago and the ever-helpful Steve Holliday then mentioned flower wasps, as he needed to again.  This time the group will spring to mind  whenever a large blackish wasp hoves into view.  (Don’t tell me, there’s bound to be a ‘FALSE flower wasp’)  From Feb 2010:

 

flower wasps_.jpg

 

    

 

From: John Rawsthorne [
Sent: Thursday, 24 March 2011 6:02 PM
To: 'pete cranston'; 'Geoffrey Dabb';
Cc:
Subject: RE: [canberrabirds] Entomology Corner - bugs and sex

 

Strange how the world goes around.  I heard this very same fascinating story of sex and deception amongst wasps and orchids while chatting with Graham Brown here in Darwin last weekend. 

 

Anyway, Graham has asked me to pass on, regarding Geoffrey’s photos, that “the wasp is almost certainly a species of the 'Lophocheilus' obscurus complex.”

 

Cheers

John Rawsthorne

 


From: pete cranston [
Sent: Thursday, 24 March 2011 11:24 AM
To: Geoffrey Dabb;
Subject: [canberrabirds] Entomology Corner - bugs and sex

 

The insect is indeed a wasp, same order as the bees (Hymenoptera). This one is a male thynnine wasp - it is winged which distinguishes from its flightless female. These wasps are stars of the screen, with extraordinary footage from Western Australia in the BBC / Attenborough series 'Life in the Undergrowth'.  They are involved in a sexual deception system involving orchids that are chemical mimics of the female wasps' pheromone lures. Simply put, the wingless female adult thynnine climbs to the top of a plant (often a grass) and emits her perfume to lure in male suitors. After a brief courtship she allows a male to take her on a nuptial flight during which he mates with her (all captured by BBC film unit). But into this straightforward system come many different orchids, which have attained a perfect or close match to the female thynnine's fragrance - hence luring  males deceived into expecting a receptive female. The orchids' shapes and colours are passable imitations of a female perched on the top of a grass blade - certainly good enough for the witless male 'victim' . He attempts to copulate with the orchid's deceptive model, whereupon he receives an orchid pollenium stuck on his rear. Not being too bright, the male repeats the sterile performance (termed 'pseudo-copulation') again and again, ensuring at least the orchid  is pollinated.
The system is complex - there are many orchids and many species of thynnines (especially in Western Australia, but also locally in ACT), and there is evidence of quite tight association between the component species. And now the male thynnine has another problem - scientists have succeeded in synthesising the chemicals in the phermone mixes, and can lure in the males for study. Amongst those researching this system is Rod Peakall at the Australian National University.
While teaching students in California over the past decade, this tale, and the footage from the BBC would stimulate even the doziest students.

Pete Cranston

At 11:38 24/03/2011, Geoffrey Dabb wrote:

You may be right Paul.  Species?  (Note patterned wings and strongly segmented abdomen)
 

 
-----Original Message-----
From: Paul T.
Sent: Thursday, 24 March 2011 10:14 AM
To:
Subject: Entomology Corner
 
 
And then the next frame has the bird on the left answering...... "No,
that is the even rarer Rainbow Wasp-eater!" <grin>
 
 
Cheers.
 
Paul T.
Higgins, ACT.
 
 
 
*******************************************************************************************************

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the Canberra Ornithologists Group mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the list contact David McDonald, list manager, phone (02) 6231 8904 or email . If you can not contact David McDonald e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU