Speeding Up!...

Emperor larvae are currently changing to the 4th instar (L4). Given that the weather is set fair, after a useful drop of rain in the Empire on the 23rd, they are likely to romp through this instar.

At this range, Emperors are likely to be on the wing in or by mid-June, but it is Too Early to make an accurate prediction (last year I was 24 hours out). I'll make a prediction in mid-May.  

This is a good time to look for larvae on early-leafing sallows, as nothing else is currently eating large chunks of leafage. Just stand under leafed sallows and look up, for missing chunks (ignore little holes, Emperors feed from edges and seldom make holes). A few Geometer moths are starting to pepper sallow leaves, ignore them.  

Here's a larva, from Glos today, who has recently changed into L4. Note the feeding marks -

Finally, here's something for fellow sallow fanatics - only the second diecious sallow I've ever seen (both sexes on the same tree), at my Glos site today.

 

Steady Progress! Skin Changing

Emperor larvae are making steady progress this early spring, in the fine weather. A few are already starting to change skins, to the 4th instar (L4). 

Most are at this stage (late-L3, feeding on leaf undersides from a silk pad on the stem) - 

Or this -

This one's interesting. He's 5m up on a sallow, trackable only through binoculars. His silk pad is next to a slow-developing leaf bud, so he's feeding on a loosening bud 10cm up-stem. You can see his silk trail running up to his feeding bud - 

It's far too early to speculate on when the flight season will begin, but some of the midsummer species are well advanced (notably High Brown Fritillary, which should be out in late May this year down south...)

High Winter Survival Rate

Delighted to be able to report the lowest level of (assumed) titmouse predation in sixteen winters of close study in Savernake Forest. We only lost one larva to definite bird predation, though another has just been listed as Missing in Action, after having woken up from hibernation...

Crucially, we didn't see a single tit flock in the forest all winter, and recorded only the odd individual Blue, Great and Marsh tits. There's a strong correlation between tit populations going down and Emperor populations going up!

However, three other larvae either desiccated in late winter or had their innards sucked by predatory invertebrates (e.g. shield bugs or Tree Damsel Bug).

Yesterday, most surviving larvae were poised next to buds, waiting for the bud to swell and loosen, so that they can start feeding. But one early bird, on a non-flowering branch that sprang into leaf early, has been feeding for over a week, has grown noticeably and will start to change skin to the 4th instar next week. Here he is -

Elsewhere, two larvae have just started to feed in Gloucestershire.

Emperor larvae are currently bang on time. This time last year they were romping ahead and were threatening to be on the wing at the end of May! There's no sign of that happening, yet.

Watch this space, this Emperor season is getting interesting...