Sunday, October 4, 2015

Oates's Marathon Innings

Today I at last reached the 1000 landmark - i.e. 1000 Purple Emperor eggs and larvae in the wild, with a pair of 3rd instar larvae close by on the same spray, on the edge of Savernake Forest. 

Unusual to find two together as, surprise surprise, they hate each other and squabble like mad - if one invades the other's leaf they lock horns and try to wrestle each other off...  

Also found a deceased larva (which counts in the 1000) - 

Note the shiny egg case base at 2 o'clock from the head.

It would be nice to think I could retire now, but I can't, so I took a fresh guard, uttered a profanity against the Two-tailed Pasha and batted on.  For those who like statistics, the innings took 40 years, lasted over 1000 hours, and included one nine, two sevens, three sixes and 24 fours...  Over half were found in four glorious seasons.

Can someone please certify me...

Wednesday, September 30, 2015

Battle of the Titans...

Just returned from a visit to my best friend from school's villa on the Costa Brava...  

Here's the view -

This was my first opportunity to look for the Two-tailed Pasha Charaxes jasius, the one butterfly I feared might rival iris for the position of Europe's premier butterfly. It's larger for a start.  I'd lost a lot of sleep worrying that jasius might prove mightier than iris.

I need not have worried.  It's a cowardly beast, which wouldn't last five minutes in the Knepp Wildlands oaks.  With such a jerky flight it would never be able to out-manoeuvre iris in a clash and chase, and would quickly be shot down in  flames.  The first one I saw got beaten up by a Red Admiral.  Imagine that!  No Red Admiral would dare to fly into an iris territory, though they often set up territories directly below those of iris.  I chose to turn my back on Charaxes jasius, and refused to photograph it.  I was wearing purple and white at the time, of course.

This establishes a precedent: from now on all People of Purple Persuasion are obliged to turn their back on their first Charaxes.  

For the record, Long-tailed Blue, Lang's Short-tailed Blue (more of a Long-tailed lookalike) and Geranium Bronze were numerous in my friend's garden.  Nigel's Pelargoniums had been suitably shredded by the latter, except for those with aromatic leaves which the females seem to ignore.  Here are the pics, I didn't bother to photograph jasius

Monday, September 14, 2015

Egg Lay Woes

Ably assisted by Mark Tutton (who seems to be better at finding iris larvae than me) I am two-thirds of the way through my annual monitoring of eggs and larvae in and around Savernake Forest.  

It is not good news.  Although I kicked off with a miraculous five larvae on the first tree I searched, the tally has since struggled to reach ten, suggesting that my final total may be a measly 15 - that's significantly lower than last year's count, which itself was the lowest recorded since monitoring began in 2009.  

Yesterday, in seven hours of combined searching Mark and I found a single 2nd instar larva and one failed breeding site (first instar feeding leaf & seat pad, + egg case base remnant, but no sign of the 'pillar).  

So far in Savernake, I am averaging one find per 3 hours searching. Brother Dennis, active in North Bucks, is doing much better, averaging one find per hour.  In 2009 and 2013 Savernake was produce a larva every 20 minutes.

There are several reasons.  In Savernake, the flight season kicked off late (mid-July), then the weather deteriorated and the females had to contend with windy and at times wet weather.  Iris hates wind.  I was not expecting a big emergence there anyway, due to a poor egg lay in 2014.  Also, most of the favoured sallows at the southern end of the forest have been rendered unsuitable this year by extensive damage by tree hopper nymphs, several breeding sallows have been badly damaged by squirrels, and others have been pruned back or removed during ride-widening work.   

This monitoring is, of course, based on the assumption that the butterfly lays the same proportion of its eggs low down annually - reachable from the ground with a shepherd's crook.  There is no evidence to support or counter that assumption...

For the record, the few larvae that are around are changing from 2nd to 3rd instar now.  

The prospects for the 2016 flight season are, at this distance, not great...

Here's yesterday's 2nd instar larva - 

And here's His Tuttonship, at the joyous moment of finding his first iris larva - 

Mark is now on 2 not out...

I am on 997 not out (accrued during a marathon innings of 40 years), but I'm not particularly confident about reaching the magical four figures this year...

Friday, September 4, 2015

Caterpillar hunting at Knepp

Knepp may have topped the table with sheer numbers of adults on the wing year but finding caterpillars is no easy task.

I must say that spending the afternoon with Matthew was an absolute pleasure (as usual), expert guidance is a prerequisite to finding the little blighters. Thankfully, earlier in the day Penny, Knepp's ecologist found one and I was able to have an introduction.

Having only found one today has whetted the appetite to find more so back to Knepp very soon.

I almost forgot to mention that Knepp has a new limited edition Purple Emperor pin badge. It is a larger, 3cm wide version of the original Empire badge. Limited to 100 badges to celebrate the 100+ sightings on a Safari this year. The badges are available to personal visitors.

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...

Sunday, August 23, 2015

Infertile Eggs

Infertile eggs are not that infrequent, perhaps especially after hot weather flight seasons.  Either that or I find every one laid...

This egg is empty.  I bunged it under the microscope at x 60 and couldn't find any hole, so it hadn't been sucked (by a weevil, or other malicious invertebrate).  The conclusion is that a male was firing blanks, or a female had run out of sperm...

(Fermyn Woods, 20th Aug 2015 - and I saw 14 Silver-washed Fritillaries, 2 old Ringlet and, incredibly, 2 old Large Skipper - my first of the month).

Wednesday, August 19, 2015

Knepp Highlights

Thanks to David Land for forwarding these magnificent photos of Emperors on the favoured sap oak at Knepp this July -