Wednesday, 1 August 2012

An Unexpected Discovery

Three times in 12 years Emerald Forest Doves have mistaken our windows as extensions of their forest habitat and have paid the price. Yesterday one bird met its fate. When I picked it up I noticed a very large (relative to the size of the bird) Louse Fly. I have written about these flies before when they showed up at the light sheet. Louse Flies are external parasites of birds and mammals in the family Hippoboscidae. You can get an idea of the diversity of the family from the images on the site.

Louse flies are remarkably adapted for existence in bird feathers. Some species detach their wings when they have found the proper host. Eggs mature within the mothers and the living larvae are deposited away from the host and they have to undergo the lottery that many parasites are forced to endure. The right host has to come along at the right time for the larvae to continue their development.

The flattened appearance of the adult likens them to lice, hence the common name. Several are parasites of livestock and are transported around the world on their hosts. Australia has several introduced species that are just such pests.

The fly measured approximately 11mm in length.

The business end. The piercing mouthparts enable the fly to suck blood from the host, probably from the feathers. The flies are very fast-moving. This enables the fly to dodge the preening activities of the bird without being harmed by its beak.

But nothing is straight-forward in this world. The odd creature below was also found within the feathers of the poor bird.
It is may not associated with this fly. It does not seem to be a puparium. So what is it? Maybe a reader will shed some light on the subject.
Frontal view. It does not seem to be a larva. It did not move and there seems to be no opening in the midst of the teeth-like structures. Any ideas?

Along related lines, have a look at Piotr's blog on another, much more robust, parasitic fly.


Denis Wilson said...

I remember seeing "louse flies" on many small birds which my father would band as a volunteer CSIRO "Bird Bander".
Always gave me the "creeps" as they were very fast moving and resistant to squashing.
They could hide amongst feathers very easily.
We sometimes found "maggots" buried partially under the skin, especially of nestlings and juvenile birds.
I have never seen a free-standing larva such as yours appears to be.
Interesting specimen.

Snail said...

No idea what that is, but I'm looking forward to finding out.

Eleven millimetres is a darned big fly for a small dove. And the hippoboscids on brush turkeys are so large that it's no wonder the birds are preening all the time. (And that they don't fly very well!)

I've been (momentarily) mistaken for a host by the small louse flies that infest the pademelons. Next time that happens, I will try to catch one for photographs.

Chris Borkent said...

My guess on the mystery object is that it is a seed (maybe from a mistletoe). Unfortunately, being Canadian, I'm not familiar with the flora of Australia so can't help any further.

Maybe someone here can help?

Mr. Smiley said...

Thanks Chris

I'll put it to the botanists.

Mr. Smiley said...

Thanks Chris

I'll put it to the botanists.

HomeBugGardener said...

Hard to guess with no idea of the size, but Heather's guess is maybe an elaisome.

Could be an infective stage of some wormy thing too.

Mr. Smiley said...

The botanists say it's "not of of theirs". So it must be some sort of parasite.

Andrzej Grzywacz said...

It is a pupa of louse fly, Hippoboscidae. Larva develops in females abdomen and when fully grown is extruded by female. Subsequently pupation takes place in the puparium. On the second photo it is in fact posterior part with posterior spiracles, not front view.

Cristian LucaƱas said...

I think the proper term would be Ascodipteron.

Getty said...

Yes, I believe it is a pupa, still unhardened, so probably aborted by one of the near-term females. It is not Ascodipteron, which is a bat ectoparasite, family Streblidae.