Only 4 larval instars in Smerinthus caecus?

Dear Klaas,

Smerinthus caecus has 5 instars, but normally they can be rather smaller than average 5th instar larvae of Smerinthus ocellatus.

Regards,
Serge

Your larvae are currently L5 now. I stated you have missed one instar.

Regards,
Serge

Hello ,

I also have problems with the zize of the larvae of S.caecus ...i don't know if they have moulted 4 or 5 times , but the size of Larvae are going to pupate is ridiculous ( above 45 to 50 mm ) !
origin from Serge

the 5 Larvae i have from you Klaas are in L2/L3

I think Autumn entered correction due bad quality of food plant. I just finished my own rearing. Pupae are noticeably smaller than in August, but anyway they 56-64 mm in length.

I used Salix babilonica.

Regards,
Serge

Don't forget Smerinthus caecus is not too big species being smaller than Smerinthus kindermanni and of course rather smaller then Smerinthus ocellatus.

I think that you're right Serge ...Foodplant is not very good at this moment ...I use Populus
Regards,
Pascal

Of course it is why you use Populus. The same problem is with Loathoe amurensis when reared on Salix.

Klaas, I can confirm her observations. My page Caecus larvae got 3 times a new skin. They have slipped on the 18.10 of the egg and dig since yesterday (16.11). one, as a L4.

Regards
Harald

me too, I have only 4 instars, caterpillars are around 6 cm and ready to pupate, raised on Salix caprea (still very good quality and still growing with a lot of fresh new leaves - I don't think it's the quality of the food causing only 4 instars, maybe the short daylight time???).

regards
Jurgen

Moin,

da ich seit einigen Wochen auch Smerinthus caecus züchte, wahrscheinlich sogar mit einer sehr ähnlichen Herkunft, reaktiviere ich dieses Thema und möchte nur kurz mitteilen, dass ich bei der Aufzucht definitiv 5 Larvenstadien hatte.

Was nun nicht bedeuten muss, dass eure Angaben falsch wären.
Aber anscheinend gibt es da bei Smerinthus caecus ein paar Unregelmäßigkeiten bei der Entwicklung.

Was mich auch verwundert ist die eigenartige "Zeichnung" der verpuppungsbereiten L5.
Bei dem ersten Tiere dachte ich, es hätte sich gegen eine Spinne im Zuchtbehälter oder gegen eine andere Raupe zur Wehr gesetzt und sind entsprechende Spuren.
Aber nachdem dies jetzt die achte Raupe ist die in die Erde geht und alle sahen so fleckig aus, scheint das, zumindest bei diesem Stamm, wohl eben so zu sein.

Deckt sich das auch mit euren Beobachtungen als ihr Sm. caecus in Zucht hattet?
Oder wie ist das mit den Kollegen, die die Art auch jetzt gerade züchten?

Ich würde mich auf ein paar informelle Worte freuen.

Gruß
Rudi

Hello,

Since I also breed Smerinthus caecus for several weeks, probably even with a very similar origin, I reactivate this topic and would like to briefly announce that I definitely had 5 larval stages in the rearing.

What does not mean that your information would be wrong.
But apparently there are a few irregularities in growing at Smerinthus caecus.

What amazes me is the strange "drawing" of the fully grown L5.
At the first L5, I thought it had defended itself against a spider in the breeding box or against another caterpillar and are corresponding tracks.
But now that this is the eighth caterpillar that goes into the earth and everyone looked so spotty, that seems to be so, at least for this tribe.

Does that also coincide with your observations when you had Sm. caecus in breeding?
Or how about the colleagues who breed the species right now?

I would look forward to some informal words.

greeting
Rudi

@Klaas
@Serge
@Jurgen Vanhoudt
@erannis

so they either have 4 or 5 instars. Other species can have five or six instars depending on rearing conditions. I don't think it's that abnormal, even though not a very common phenomenon, it has been reported before (I at least remember a similar discussion for Argema)
The somewhat unhealthy look just before pupating also seems to be normal for this species. I first thought mine were dying, but they all pupated normally and the pupae also hatched the next year.

Hello Jurgen,

Thank you for the feedback and opinion!

As the discoloration of the L5 looks like, I might think she wets herself with a secretion before she leaves the feed to look for a pupation place.
However, I could not observe any of my animals in such behavior.

Is somehow dubious.

hallo Jurgen,

danke dir für die Rückmeldung und Meinung!

So wie die Verfärbung der L5 aussieht könnte man meinen, sie hat sich selbst mit einem Sekret benetzt bevor sie das Futter verließ um einen Verpuppungsplatz zu suchen.
Allerdings konnte ich keines meiner Tiere bei einem solchen Verhalten beobachten.

Ist schon irgendwie dubios.