Sunday, August 30, 2015

Larval Doings...

The larvae hunting season is upon us...  I have neither the time (in late July & early August) nor the eyesight to search for eggs, preferring to look for 2nd and 3rd instar larvae on leaf tips instead, from late August through to late October.  The disadvantage of this is that one finds failed breeding sites - egg case bases and 1st instar larval feeding damage, with no sign of the 'pillar.  That, to me, still counts as useful information, and occasionally the missing 'pillar is found later.    

For the last six years I've methodically searched for autumn larvae in designated areas in and around Savernake Forest in Wiltshire. The search area takes some 40 hours to cover.  

Last year's Savernake tally was the lowest in the six years.  I was fearing that this year may produce an even lower count, as adults seemed horribly scarce there in July, and so was greatly relieved when I kicked off with six larvae yesterday - on trees which produced two failed breeding sites in 2014.  That's reassuring.  

This week I'm going to spend three days searching for larvae at Knepp (and looking for Brother, or rather Sister, Betulae). The objective is to compare overwintering mortality rates at Knepp and Savernake.  A sample of ten hibernating larvae at both sites will do - anything more than 25 is unmanageable.  

If any Sussex locals want to join me on Tues, Wed or Thurs, even for the odd hour, then please come along (text 07771 971488). Warning: experience suggests larvae are not that easy to find at Knepp.  Any larvae found there will be named after Burrell ancestors (Knepp estate family) and closely monitored.

Here's a late second instar larva from Savernake yesterday - 

And a 1st instar larva skin changing there yesterday -

I also find a fair few of these, as Pebble Prominent moths favour the same type of sallow foliage as iris -

Watch this space, nothing might happen but watch it anyway...

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