Does anyone know incubation time for nuclear polyhedrosis

[Gwynne]

I was wondering if anyone knew the incubation time for nuclear polyhedrosis? Two days ago, I lost two young caterpillars. They were in separate containers and both turned black. I looked at pictures of diseased caterpillars and they didnt resemble anything OE. They werent a perfect match for nuclear polyhedrosis either, but resembled that slightly. Eight other caterpillars were exposed to the first two. It is almost 2 days later and so far those caterpillars are doing well.

What I cant seem to find out is if there is any sort of incubation period. If they were exposed two days ago, could they still become sick? Could they become sick in a week? I was hoping to raise them in my new monarch life castle with 9 caterpillars that are two or three days older than them, but cant do so unless I find out it is safe. Does anyone have any ideas or can they point me in the correct direction as far as reading material? Thanks!

[Jim]

If the others have a virus you should be seeing signs...sluggishness, lack of feeding, wet frass, loss of coloration, etc. Once infected, the virus replicates rapidly and can kill the larvae within a few days I believe.

You could also be seeing a bacterial infection...here are a couple of photos:

http://faq.gardenweb.com/faq/lists/butt ... 31715.html

Either way, it is a good idea to wash leaves you feed to your cats with warm soapy water (rinse well!) and keep rearing chambers clean and dry. Isolating your caterpillars is another way to prevent transmission of any disease. If you suspect infection, sterilizing your containers/chambers with a 20% bleach solution (again, rinsed well) is crucial.

[Gwynne]

Thanks for the information. Everyone seems to be healthy since them. I am hoping it was just a fluke or a couple of weaker caterpillars. Even breeding in captivity, there must be some that just dont make it. My caterpillars looked nothing like the photo, just had some black on them. I am hoping I let my imagination run away with me, sort of like watching a horror film alone just before going to bed!