Welcome to my world..............

Sunday, 18 September 2016

Copper Underwings

That time of the year again and I have had a small number of Copper Underwings sp.  I am aware of many of the stated differences between Copper Underwing and Svensson's Copper Underwing but am also aware that some of these features are not reliable and Les Hill is studying the species pair in some detail.  Having found one in the house dead which was the well-marked one from Brimham a couple of weeks ago, and escaped while photographing it in the hall at home, I spent some time checking over the individual.

The main features to check are as follows:

1/  Check the palps to see if pale (CU) or dark with distinct pale tips (SCU)

2/  The extent of the copper on the underside of the hind wing - restricted to terminal band (CU) or extending up towards the base (SCU)

3/  General colouration and contrast - very contrasting (CU), or not so (SCU) indeed Svensson's has been known as 'drab' Copper Underwing

4/  The two major points on the crossband - draw a line joining the two and extend to the outerwing - if directed towards the back of the wing (CU) and if slightly forward towards the base (SCU)

5/  The black and white markings on the sides of the abdomen - contrasting and well-marked in CU, less so in SCU

Of course some of these features are subjective and open to interpretation, others appear more clear-cut.  When applying these checks to this individual it throws up some interesting points.

1/  The palps.  In this individual they are clearly dark with pale tips indicating Svensson's.

2/  The extent of the copper on the underside of the hind-wing - limited, indicating Copper Underwing. (In the photo there is some shadow and a faint suggestion of darker copper extending towards the base but in reality and good light this is not so).

3/  General colouration - strikingly contrasting, suggesting Copper Underwing.

4/  The two point tips. joined by line and extended to wing edge - backwards suggests Copper and forwards Svensson's. On this one forwards indicating Svensson's.
5/  Abdomen markings - contrasting black and white suggesting Copper Underwing.

All in all, five features, three suggesting Copper Underwing and two suggesting Svensson's Copper Underwing.  I know many observers use the palps as the main (only?) feature to distinguish the two, but this one individual shows that it is not as straight forward as one would think.  I think this one is going to have to have its bits done to confirm, something I have done very little of but really should on this occasion, especially as it is already dead.  Watch this space....

No comments:

Post a Comment