Saturday, February 25, 2012

Searching for Pupae

Matthew commented on Guy's blog:

Very interested in how / where you foundthe two pupae? In Savernake, they are all but impossible to find – even after placing out full grown captive bred larvae on medium size bushes -, so much so that I suspect either very high losses or movement on to different trees. And Idon’t find old pupal cases whilst looking for eggs / larvae either. But the Savernake sallows are tall… though I scan for pupae with binoculars.

Guy replied:

Both these pupae were at about head height in sallow about two bushes distant (but connected by touching branches) from where I had been watching two caterpillars. They were very well camouflaged and each time I went back to see them I had to stare for some minutes to relocate them. Here is one, in context (just left of centre):


And close up:

And here the other:


A third caterpillar I was following that year was nowhere to be found after his final instar. I do think he survived, though, as a she, as an egg was subsequently laid on a leaf right next to what had been ‘his’ resting leaf, giving birth to Hadrian:

One pupa died – Neil followed the drama as it unfolded on UK Butterflies. The other simply disappeared, when I thought it should be emerging. The cluster of sallow where Aurelian is currently hibernating is rather small and if he does survive that long it should only require patience to locate him.

At this point, Neil joined the discussion:

The only two pupae I have found in the wild (on ‘The Magic Sallow’ on the Downs at Amberley – killed by squirrels, then resurrected) were actually very close to where I had watched a handful of caterpillars approaching maturity in 2007, both being just above head height. These observations were greatly assisted by ease of access to the site, with almost daily visits possible (still hard to track them!). An elderly microlepidopterist who retired to Storrington from Aberdeen a few years back subsequently found an empty iris pupa (!!!!) on the same bush in July 2008, again just above head height.

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