Monday, April 22, 2013

Out of Hibernation

Wild larvae were checked on Saturday 20th.  All bar one were out of hibernation and greening up, getting ready to start feeding once the leaves unfurl (sometimes the odd hungry one jumps the gun and nibbles a leaf bud before it opens).  The one retard is lined up next to a late-developing leaf bud on a late-leafing tree in a cool location, so must wait a little longer.   

The larva we've been following all winter has moved >2m up to the end of a leaf spray that will open soon.  He has also greened up nicely.  Here he is -

And here's the silk pad he wintered on -

Sallow leaf buds are swelling fast.  Interestingly, most of the trees I'm following larvae on are not going to flower this year, which means they will come into leaf quite soon.  In past years larvae have had to wait ~10 days for the trees to flower, before the leaves open.  Many of the breeding sallows in the forest seem to be having a year off from flowering, perhaps as a legacy from last 'summer'.  I have not noticed this before.

Just because larvae have emerged from hibernation a bit late this spring does not mean that the adults will appear late.  That depends on weather during May, the larval growing month, and June, the pupal period. 

But now is the time to prospect for new iris localities - whilst the sallows are flowering.

Wednesday, April 17, 2013

Out of Hibernation

Yesterday, Tues April 16th, two of my three captive larvae came out of hibernation and aligned themselves next to swelling leaf buds.  I suspect they are also waking up in the wild... 

Tuesday, April 16, 2013

Abberation and Gynandromorph?

I spotted this for sale on eBay and it is listed as ab. semi iole however whilst there are indeed less white markings on the right hind wing both right wings seem decidedly larger than the left? Could it be a bilateral gymandromorph perhaps?
Mark T

Sunday, April 14, 2013

Latest Wild Doings

Checked all wild larvae today.  All present and correct, and healthy.  So none of them desiccated during the ten day spell of bitter north to easterly winds (though none was in a place significantly exposed to those winds). 

Having followed larvae through in the wild for four winters, it appears that 'desiccation' is more of an issue in captive breeding than in the wild.  I have recorded one 'desiccated' wild larvae in four winters, out of >100.  One thing I can say quite categorically is that iris larvae behave very differently in the wild to how they behave in captivity.  They are almost different animals.

Other good news is that, with a few days to go before larvae come out of hibernation, this winter's loss to (assumed) tit predation is under 20%, compared to >60% in the first two winters (varying sample size though).

Friday, April 12, 2013


It may (initially) only be 7 amino acids, but early indications from data recently obtained would implicate that his majesty has a Pheromone-Binding-Protein (PBP) homologue. You heard it here first. More to follow...

Monday, April 8, 2013

Desiccated Larvae

One of my four captive larvae seems to have shrivelled up and died.  This seems to be a familiar problem to those of us who breed iris, occurring in late winter / early spring.  But what causes it?  Is the bitter east to north-east wind which has plagued us for almost a month responsible?   

I need to check the wild larvae again, to see if they're alright, but in three years' recording to date I have only once had a wild larva desiccate. 

Wednesday, April 3, 2013

March Larval Survival

Delighted to report that none of the nine larvae I've been following in the wild was lost to predation during March.  That is quite an achievement given that predation levels (seemingly by tits) are highest during the late winter period.  So far I have lost only two out of 11 larvae this whole winter, though winter is far from over and larvae will be late to commence feeding this year.  In other winter's two-thirds of larvae have been lost of predation. 

This winter, tit numbers appear to be down, presumably due to poor breeding success in last spring's rotten weather. 

Although it's still early days I am minded to revise my prediction for this year's adult emergence upwards - though so much depends on weather during the pupal period and, especially, the flight season.  So, finger's crossed, this butterfly may well be on the up again. 

It is far too early to predict when the butterfly will be flying this year.  That depends on weather during May (larval growth season) and June (pupal period).  The fact that spring is late is irrelevant at this stage (iris larvae tend to do very little before the end of April anyway), though the sallows are likely to come into leaf late.