Case moth

[JRsbugs]

Hi,

Now I need help!

Taken on 17th October on the side of a plant pot in a greenhouse. Approx 15mm long but I haven't measured it yet. Psyche casta is a possibility but I haven't found what size it should be. This one has small stones on it, which I haven't found any of this type of moth uses as camouflage. There appears to be a larva inside, with the inner case in readiness for the mature moth which is something I have read the male of Acanthopsyche atra does.

Any clues? In the greenhouse I have a variety of plants including citrus, crinum, ferns, fuchsia, zantedeschia, dracunculus, etc.

Janet

[JRsbugs]

I found that Acanthopsyche atra feeds on certain grasses including Gramineae which includes bamboo. I have one just outside the greenhouse in a large pot, but I also have other grassy plants such as Dierrama.

Acanthopsyche

Some pics I found which look very similar,

Bestimmungshilfe des Lepiforums: Acanthopsyche Atra

It's not listed on the NBN Gateway, but not everything is.

[JRsbugs]

I found Psyche casta is 8-12mm long, so it doesn't look like it's that and there is of course the bag thing at the bottom.

Psychidae

[charlieb]

Have you seen this: UKMoths ?

[JRsbugs]

Originally Posted by charlieb

Have you seen this: UKMoths ?

Yes Charlie, first port of call!

The size they give for the male is far bigger than mine, I have measured it this morning and it is 15mm tip to toe including everything. Hants moths gives the size as less, from 18-24mm which is close unless that doesn't include the bag at the bottom.

Hants Moths - 0191 Acanthopsyche atra

I think I should send this to the county recorder to see what he thinks, I haven't come across any mention that Psyche casta does the bag thing.

[charlieb]

Originally Posted by JRsbugs

There appears to be a larva inside

I was wondering if it's been and gone? - They're said to fly April/May - could it be an old case? (although if the greenhouse may have messed with its timings)

[JRsbugs]

Originally Posted by charlieb

I was wondering if it's been and gone? - They're said to fly April/May - could it be an old case? (although if the greenhouse may have messed with its timings)

I doubt it has gone, look carefully and you can see a creamy coloured larva just below the case. From the front you can see some small marks on what appears to be two sections. I read somewhere this is what they do, protrude a few millimeters out the bottom. They likely pupate over winter, must look again to see what I found!

[charlieb]

Can't see any larva myself...

That looks a lot like an empty pupal case sticking out the bottom to me - it also looks like its been fixed to the side of you plant pot.

[JRsbugs]

Originally Posted by charlieb

Can't see any larva myself...

That looks a lot like an empty pupal case sticking out the bottom to me - it also looks like its been fixed to the side of you plant pot.

It has been fixed to the side of the plant pot, and it is supposed to do that in April to June before emerging. There's a big but here though, as stated on ukmoths..

The long-lived, often for two years, larva usually stays on or near the ground, rarely climbing up plants.

This could be hibernating for the winter in it's first year! The pot is on the first shelf of staging from the ground.

If you enlarge the pics more you should see a fat creamy coloured grub just below the debris.

[charlieb]

Originally Posted by JRsbugs

This could be hibernating for the winter in it's first year!

But fixed?

Originally Posted by JRsbugs

If you enlarge the pics more you should see a fat creamy coloured grub just below the debris.

But whats the orange pupal-coloured thing then?

[JRsbugs]

Originally Posted by charlieb

But fixed?

I'm only guessing, but as they can take up to two years maybe it just fixes itself earlier than usual....

But whats the orange pupal-coloured thing then?

The orange pupal thing I think they drop in readiness to emerge, but I need to read up again on that. Now I must go out to get some of this glorious sunshine!

[JRsbugs]

I took closer pics of the front and side view of the pupal case. If you enlarge them more you will see something I think! The front view seems to show a couple of legs, or I have a good imagination, they look double.

This is what I read on ukmoths,

Shortly before and during pupation, the male case can be recognised by its posterior extension (about 6 mm) of a grey silk sleeve, devoid of plant fragments. After emergence, the pupal exuviae fills and protrudes from the sleeve.

If that is the 'case' then it could be the warm weather we have had, plus being in the greenhouse has triggered imminent emergence! The case isn't grey either, but is the same colour I see elsewhere or maybe it starts grey and turns orange.

Look carefully at the side view, the case looks to be stiched with white waxy stuff, how it would do that I don't know unless it went back in the top and sealed that afterwards. Or is my imagination running away with me!

[JRsbugs]

I posted this elsewhere, it is Psyche casta. The size to the bottom of the case does fit, at 9mm with a 6mm extension. It emerges May to July but it doesn't state on UKmoths when it starts to pupate. I haven't seen anywhere about them making the extended pupal case either.