Friday 20th May 2011 - Shenstone

This morning's walk around the patch was more of the same in terms of birds (or lack of).  Still it was nice to see Common Whitethroat displaying and here the Skylarks & Linnets singing.  There were 14 Swifts over Heath Lane.  Kestrels were seen both here and Butts Lane. 6 Common Buzards (2 juveniles) were in the Back Lane/Curslow Lane area, one of the adults was a stunning light phase individual with a white head and chest.  

So with things quiet on the bird front I decided to spend some time at the entomological hot spot of Butts Lane.  The first thing that was noticeable was the amount of 'cuckoo spit' there was on the various plants.  Cuckoo spit is the common name for the white, frothy substance produced by Froghopper nymphs as they feed inside plant stems.  It is the undigested excess plant sap that they blow out of their back end to hide them from predators.

The weather wasn't ideal for butterflies but I still managed to see 1 Brown Argus, 2 ♂ Common Blue, 1 Small Copper and a Small White.  I also disturbed (unintentionally may I add) a Cinabar Moth.  A number of ♂ Thick-legged Flower Beetles (Oedemera Nobilis) were also noted.

It can be tricky identifying Brown Argus from female Common Blue when the wings are closed but there are a couple of ways.  The easiest is to look at the spots on the underside of the hindwing.  Two of the spots on the leading edge of the hindwing are relatively-close in the Brown Argus, almost forming a "figure of eight" or a "colon" shape.   In the Common Blue the hind wing spots are more evenly spaced apart, with only a single spot in the position where the Brown Argus has two.  I was lucky enough to get photos of the undersides of both the Common Blue and Brown Argus today and have put together a picture below highlighting the difference. 

Brown Argus & Common Blue comparison:
Double-click on photo to view larger image

Brown Argus:

Common Blue (♂):

♂ Thick-legged Flower Beetles (Oedemera Nobilis):


  1. Lovely photos again Jason. I can remember being very confused between the ID of Brown Argus and Common Blue a couple of years ago. Your 'side by sides' show the difference well!

  2. I'll have a go at looking for those spots Jase :-)

  3. Thanks Shy...much appreciated.

    Ha Warren...Now I know that I dont need to educate the likes of yourself in the difference between the species!...but there are other none bloggers who read it who may find it useful...either way I had fun putting together the side by side photo