Oryctes rhinoceros nudivirus in A. dichotoma?

[Buggly McEsabug St. Bug]

Entomology Today released an article regarding larvae of Allomyrina dichotoma being infected with a virus and threatening the beetle business in Korea.

I'm probably being a little bit paranoid, but with only the one photoset and decription to look at, I'm worried about the dichotoma larvae my friend rehomed to me. Some of them are a little squishy/soft to the touch and none of their abdomens are particularly dark like the healthy one shown in the photos. However, none of them have prolapsed rectums, as far as I can see.

I've only had them for this week, so I can't imagine I already did something wrong to them- but nonetheless it doesn't hurt to be careful. Does anyone have any more identifier tips so I can ensure whether the beetles are safe and healthy? I can provide photos if necessary, but I'm not sure yet how old they are.

Thanks in advance for your help!

 

[Ratmosphere]

Unless they were raised in Korea, I think you should be fine. I suggest posting some pictures so we can help out more in depth.

 

[Buggly McEsabug St. Bug]

It occurs to me now, after doing some reading, that they might just be pre-pupal, as they appear a little bit yellow. Here is a photo!

I'm sure I was being paranoid, but it never hurts to be careful.

 

[GeneralZero]

Definitely pre-pupal. I know what you mean though I can be overly cautious as well. Interestingly enough I find the larvae stage the most interesting to me, not sure why. I suppose it just feels good to raise something up into a healthy adult.

 

[Bill Myers]

Yup, like GeneralZero said, difinitely pre-pupal. It looks healthy enough. No prolapsed rectum, nor abnormal inflammation of the posterior segments.

According to the graph in Oxford's Journal of Insect Science, they lost about 50 percent of them within 3 weeks after inoculating them with the virus. So, I'd say if you still have most of them after about 4 weeks, then you're just fine.

Just be sure to keep them separate.

Cheers

 

[Oak]

Doesnt look like pre-pupal to me, or else their guts would have been emptied out. Also, it doesn't look that wrinkly. I would say wait another month or so for them to become prepupa, since Mid April - Mid June is when they usually pupate.

 

[GeneralZero]

Wouldn't the yellow signify pre-pupation though?

 

[Matt]

Not necessarily. The yellow colour means that the larvae is reaching maturity, the yellow is fat it has laid down in the body tissues. However, this does not always mean the larvae will pupate shortly as there are other cues that are involved in triggering pupation - I have had male Dynastes hercules larvae kept in isolation in this condition for 6 months or more before they finally pupated.

The pre-pupa is a very specific stage of the insects life. The larvae builds a pupal cell, voids the contents of the gut, stops moving and shrinks slightly. At this point the pupa is developing inside the last larval skin. All larvae are "pre-pupal" as this is the stage before the pupa, but it is important not to confuse the two terms "pre-pupal" and "pre-pupa" as advice about management of pre-pupa is all directed towards the immobile stage.

I'd call this a mature larvae, but it is not a pre-pupa.