Samia ricini

Hi!
Maybe the larvae have got some infection with bacteria! Do they have diarrhea? Are they loosing a lot of liquidly ingesta?
Once i had the same problem with my ricini-larva when i fed them with Prunus laurocerasus! In this case the larva were infected with Aeromonas sp., a bacteria wich killed all my larvae! The next time i fed them with Ligustrum and Ailanthus and everything worked good!

Maybe there is a link between feeding plant and immunity of the larva. It would be really interesting if there is some consense!

Best regards and good luck!
Lukas

Hy Lorenzo.

Could you make some fotos of your living and died caterpillars?

Rudi

Hi!
Normally such toxines aren´t the problem. A lot of insects do have enzymes that can inactivate these toxines or they have the possibility to incorporate them and use them for their protection.
Maybe there is really a link between feeding plant and immunity. I have no further information.
What i know is, that adult moth which were not fed with their natural host plant have sometimes problems with copulation. In this case foreign plant-pheromones are the reason that they cannot build their own rigth pheromones. So male moth have problems to find the females, due to the wrong pheromones.
So, I try to feed my caterpillars with the correct host plant. Therefor you get the best quality of moth with the best fertility and a strong and powerful next generation. Another positve effect is, that the colours of the moth are the colours you can find in naturally found moth.

I hope I could help you in any way!

Yours,
Lukas

Hi!
Normally it should be no problem when you change the host plant! Especially if you are using Ligustrum. They accept it much better than Prunus laurocerasus!
Try it! You will see the better acceptance!

Yours,
Lukas

Hi Lorenzo,

Sorry to hear about your problems with eri, do you have ricinus or cassava as this is normally the host used and ,most accepted.
I cant comment on prunus as never tried, or will, as for changing host plants, normally larvae wont accept this until they are third instar , then no problems.
Yes if they are dying then try the change, but if already weakened then,sorry but its not looking good longterm.
Try raising humidty,and temp a little, are the petri dishes with lid? do they have tissue in them to climb on too /to hold onto etc?
if i can help with anything just pm or email
regards

Rob

There might be a problem with toxins from Prunus laurocerasus in low ventilation. I have often used it as a foodplant with mixed results. In large netting cages I have Gonimbrasia krucki larvae feeding happily on a mix of both the Prunus laurocerasus and Eucalyptus gunii, yet I lost a brood earlier when in a warmer, less well ventilated cage,on the same foodplants, co-incidence perhaps ? A few years ago I was rearing Actias selene on Prunus laurocerasus, they were doing well, but I ran short of foodplant and shifted them to Rhododendron, they fed on it but were all dead with a ghastly prolapse and liquid frass within days !! The question is , was this a mixture of food toxins or a coincidental disease outbreak ? Regarding Samia ricini I have only reared on Privet, though Samia cynthia did well on Sweet Bay !