Grizzled Skipper pupa

[Trev Sawyer]

Woo-hoo! Even more exciting than "football coming home" at the weekend, I discovered that the slow-growing Grizzled Skipper caterpillar I've been fostering since it was an egg had finally decided to pupate The second photo shows a close-up of an eye and a black thoracic spiracle through which oxygen and carbon dioxide can pass. Apparently too much oxygen is toxic to the growing insect and the spiracles stay closed for extended periods of time - either opening fully or "fluttering" to maintain the correct balance of respiratory gasses inside the pupa.

[Pauline]

Great shots Trev and interesting details. When you say 'adopted', is this wild? semi-wild? reared?

[Trev Sawyer]

I suppose you'd call it "semi-wild" now... I saw the adult lay the egg right on the edge of a very busy footpath and felt it's chances of survival were next to zero there, so I thought I'd see if I could get it through myself... I only tried with that one egg and wasn't really expecting to succeed, but once it hatched, I put fresh cinquefoil leaves from my garden into the small petri dish I housed it in and it had been coming out from it's shelter occasionally and leaving frass as evidence it was still alive. I emptied the frass out every time I changed the leaves and eventually it stopped eating and left me no more little signs. After a week or so (last weekend) I carefully opened up the curled leaves to discover the pupa inside. If it makes it through the winter and hatches out, I'll take it back where I found it.

I did the same with a White-Letter Hairstreak which was on a piece of low-hanging Elm tree branch which had been half snapped off by highways workers strimming the roadside bushes during the first lockdown... I took the branch home and although I couldn't see any eggs or larvae, kept the twig in a bucket of water "just in case" until it started to dry up. Just as I was going to throw it away, I noticed black frass on the paving slabs underneath it and after a careful search found a fully-grown caterpillar. This pupated and hatched into an adult and was returned to its original tree early the next morning after a brief photo session.

I don't always succeed and two attempts at getting Purple Hairstreaks through to adulthood over the past couple of years with eggs from wind-blown Oak twigs have failed - the furthest one got was third instar before succumbing to some unknown malaise One day.

[Pauline]

Thank you for that explanation Trev and very well done on both accounts.

[Trev Sawyer]

Thanks Pauline.
I'm extremely impressed by your diary photos of the various life-stages... especially the hatching of pupa and eggs... you must spend ages waiting for the first signs of emergence

[Pauline]

That's very kind of you to say so Trev - it certainly does involve an awful lot of waiting and watching but to actually see it happen is amazing. Perhaps you could do it with your Grizzled Skipper?

[Pete Eeles]

Great work, Trev!

We have so much to learn and I'm convinced that captive rearing has its part to play.

Cheers,

- Pete

[Trev Sawyer]

Thanks Pete - long time no see!

It was extremely helpful to have your brilliant book to tell me how long each of the various stages would likely last. I only saw the caterpillar a few times (I should have taken more photos), but could easily tell which instar I was looking at and know that things were progressing as they should.

[Pete Eeles]

Careful - I might quote you on that Seriously ... yes, it would be good to catch up. It's been way too long!

Cheers,

- Pete