Posted by pierred on 17-12-2006 10:22
#1
Hello,
A member posted following photos (from Sardinia) on a French site and we all thought about Lucilia, but could a Lucilia get such a bronze colour with the time?
Pietro Niolu : Italie : 31/7/2006 : Villanova Monteleone : 07019
altitude : 550 m. - taille : 8 mm=po=
ref=15552
Pietro Niolu : Italie : 31/7/2006 : Villanova Monteleone : 07019
altitude : 550 m. - taille : 8 mm=po=
ref=15553
Thanks for any comments.
Edited by pierred on 17-12-2006 18:34
Posted by Tony Irwin on 17-12-2006 11:45
#2
Hi Pierre
As this appears to have only one pair of post-sutural acrostichal bristles, I think it's more likely to be
Neomyia cornicina (Muscidae). But the colour change applies to all these metallic green flies, including
Lucilia (Calliphoridae) and
Gymnocheta (Tachinidae).
As the fly gets older, the cuticle changes physically. I'm not certain exactly what the changes are - possibly the chitin layers of the cuticle begin to separate, but the effect is that the colour changes from metallic green to metallic blue or bronze or sometimes a metallic red. That this is an age-related change is evident from the condition of the wings in these old specimens (clearly shown in your top picture).
Other flies, such as
Bombylius and
Pollenia, lose their hair as they age, while in others such as
Notiphila, the pubescence can change colour from silver to gold or yellow to brown.
It all makes identifying flies a real challenge sometimes! :D
Edited by Tony Irwin on 17-12-2006 11:47
