Thread subject: :: Ariasella lusitanica, Hybotidae

Posted by jorgemotalmeida on 16-03-2008 05:35

The story:

I went to Oporto to meet Andrade and him brother. Our target: hunting to the new hybotid. There were some episodes before we could reach the place though. :P The weather's forecast (for North) was intense rain. :P But even with this forecast I drove 150 km from Viseu to Barcelos and after 100 km I could reach to Oporto city (PORTO) and there I found my friends Andrade and him brother. ;) When we reached to the place (near Barcelos), the sky was almost clear and the clouds were very far... rain, yeah.. :P Very quickly we almost run so we could take 2 hours in the field before sunset. :S It was about 5.10 pm when we arrived near Barcelos. The local is protected by Pinus cf. pinaster trees around. No feel of intense wind which is good. ;) After 5 minutes, we found the first hybotid! hooray!! and it was a male! Great! :) The hybotids run so fast, they are so irrequiet.
They can almost pass unnoticed. They are *really* very small (around 2 mm - 3 mm) At unaided eye it is not easy to discern the vestigial wings. :S (Continuing..) Well, then.. we found another one... and more... and the count was in 5 WHEN we saw two hybotids copulating!! This way of copula is rather strange and hilarious. :D The female, all the time, pull the male. The male never moved all this time. He seems so relaxed (it seems in high...) and the female always run around but not so fast of course. The "dead" weight difficult her locomotion. Sometimes we could see the female uplift her hind legs and massaging her abdomen, the male... always quiet... very quiet... it seems that he thinks: "this is so boring"... :) The copula lasts over than one hour, we could not know about the beginning. Unfortunately, they finished their copula because we caused inadvertently the separation (it was very late! almost 7 pm... :|).
You can see the videos here in my youtube:
http://www.youtub...cDrPbyA__c - female uplifting her hind legs during the copula
http://www.youtub...ea4NEAnYUk - as you can see the male is always quiet as he was nearly dead... the female.. poor female... wandering with that weight! :P

Male - vestigial wings; true dorsal (?) bristles curved on tibia of the first pair of legs; head with a very curious suture; plumose antenna near the base;

Female - clearly no wings; swollen abdomen; bigger in size in relation with male (but the difference is not evident); legs more darker than the males; scutum and scutellum almost bare; curious the fact that the female has a much more plumose antenna (more conspicuous than the male): legs much more bare than the males - has some microtrichia in ventral fore legs; both have 3 ocelli(very small and around 0,1 mm?)

Curious things - they jump when we took them in a stick and if this stick is around 10 cm to the ground they jump. They are very sensitive to movement, and maybe to the flash light, but clearly very sensitive to movement. They can be much more quick than a normal phorid fly, but not with many change of directions. On the ground, I never see them jumping, only wandering and running.

- why the female spent so much energy to load/transport the male... ?
- why the male remains almost like a dead fly during the copula?
- where they put the eggs??
- what is the time that it takes to get out since egg- imago stage?
- what is the best time to spot them?
- Is this species really common or very localized?
- it seems that this species is tolerable to the pollution... the local has some degree of pollution. Is it possible to use this species to know if the local is free or not of pollution.. I mean: Can we use them for a good pollution level indicator?


Thanks. And for the final... a silhouette of this fantastic fly.

and yes... we have hybotids for Paul, Adrian and Igor. I will give them to Andre in next week. I hope he can go to the Coimbra... :)

Edited by jorgemotalmeida on 16-03-2008 16:19