Upsetting Setbacks...

[Diao]

While doing my daily checks of all my scorpions I found one of largest Gigantometrus swammerdami inexplicably dead. She wasn't old, having only matured at the beginning of last year. On top of that, she was gravid, I was hoping for her to give birth late summer or early fall.

This is an incredibly upsetting loss for me, and although I do have other gravid females this one being of such a large size and that it was going to be is first brood I was really hoping for a large number of babies. Along with good genetics for size, too.

Best myself and a few other friends who are well regarded G.swammerdami breeders can figure is the somewhat recent introduction of using crickets as feeders. I had recently had a more outbreak in my dubia colonies, which in turn were being spread to my other enclosures, especially when there were leftover bits of uneaten roaches for the mites to feast upon. Until the mites were eradicated I had resorted to using crickets from my local pet store as main feeders alongside my other standard worm feeders used for variety. Recently, however, I had noticed that the crickets were dying much faster than usual while waiting to be fed off, and I found out there was some kind of neurological virus causing paralysis and quickly thereafter, death. I was assured by a few well respected individuals that these infected crickets were perfectly fine to feed, and they had been doing so with their tarantulas for years now with zero issues. However, I'm beginning to suspect that isn't the case with scorpions. Since adding crickets to my arsenal of feeders, I have had multiple unexplained deaths that have all had one thing in common, the last thing feed to these individuals was crickets from my same local part store that receives crickets harboring this virus.

I've also noticed similar behavior with these individuals in the last day or two before their death. They consume some of these crickets one day, then the following day I notice they aren't in their hide during the day, but are instead out exploring their enclosures, usually seeking out some high ground. The following day these individuals are then found camping out in whatever spot on their enclosures that are directly under or closest to their heat lamp. Even when disturbed, they refuse to leave the hot spot. The following day, they are dead.

I'm parting this as a warning to others, that if you have purchased crickets that you notice are ending up laying on their backs or sides, twitching or dying seemingly out of nowhere or very fast, there is a good chance they have this virus, and should be fed to scorpions only with great caution. They might be fine with tarantulas, but scorpions do seem to be vulnerable to it. All the ones I've lost have all been at a vulnerable time in their life. Two were lost by eating a large amount of the crickets as their first meal after a maturing molt. This last one was gravid, where nutrition is crucial and dedicates a lot of resources to developing the offspring, possibly putting itself at risk. I've also lost a few young instar juveniles (i2-i3) that were cricket feed right after or before molting.

I can't say with 100% certainty these infected crickets are the culprit, but the evidence is surmounting, and I would hate for anyone else to suffer any losses from something that could be so easily avoided.

Has anyone else noticed anything like this with cricket feeders, or had any other similar issues?

 

[Andrew Clayton]

How long are you're crickets lasting and what breed are they? I'm asking as this happens with me. I only have 2 scorpions though and a Dubia colony that is the main feeder but I buy small banded crickets (Gryllodes sigillatus) for some of my slings and the grown on ones I feed elsewhere (the scorpions do get them) I've had no issues so far with them. Is there any other way to tell if they have this virus?

 

[Delta9]

I've lost a couple centipedes in the past where someone said it could be the crickets. Before dying they would get sluggish and somewhat paralyzed and start twitching, losing function of their legs and sometimes dragging parts of their body. I never figured out if it was just old age or they got sick from something.
I've never taken time to ever observe the crickets themselves, but thanks to your post I'll look out for these symptoms in the future.

 

[Diao]

How long are you're crickets lasting and what breed are they? I'm asking as this happens with me. I only have 2 scorpions though and a Dubia colony that is the main feeder but I buy small banded crickets (Gryllodes sigillatus) for some of my slings and the grown on ones I feed elsewhere (the scorpions do get them) I've had no issues so far with them. Is there any other way to tell if they have this virus?

These are not the new banded crickets that you're speaking of, those have actually only come into popularity due to this virus that is wiping out the standard feeder cricket species (Acheta domesticus) that we've seen in the hobby for decades and decades. This virus, know simply as cricket paralysis virus (CrPV) has been rapidly spreading through suppliers populations, thus we've been seeing the switch to these banded crickets. I haven't really give them much of a try, as they have been problematic for me since they can jump about 3 times as high/far as the house crickets, and they are known to be more aggressive and attach their cage mates (AKA decide to snack on a vulnerable molting arachnid).

There are suppliers that haven't had the virus make its way into their populations, but it is apparently HIGHLY transmissive, so some farms are even making this switch over to bandeds just as a preventative measure. That said, the only way I know of to identify the virus is once the cricket is already symptomatic, AKA laying around and twitching, or seeing it leaving its back legs limp during locomotion. At which point, its obviously too late, and it has most likely spread it to the remaining members of its enclosure as well. Some seem to be more resistant to it than others, but If I have 100 crickets in a cricket keeper, the first day I'll see probably ~20 showing signs, maybe 15 the following day, and I've usually fed them all off by the day after that, with even more showing symptoms.

I've lost a couple centipedes in the past where someone said it could be the crickets. Before dying they would get sluggish and somewhat paralyzed and start twitching, losing function of their legs and sometimes dragging parts of their body. I never figured out if it was just old age or they got sick from something.
I've never taken time to ever observe the crickets themselves, but thanks to your post I'll look out for these symptoms in the future.

I'm so sorry for your loss, it's gut wrenching to have to watch it happen slowly like that when there is nothing you can do to help. This is exactly the same way the symptoms show up in the crickets, and almost exactly the same way it presented itself in my scorpions. With the scorpions, it would start by their tail going limp (common with other ailments as well, so not super indicative by that alone), followed by difficulty with locomotion, if any walking around at all, and very slow labored leg and pedipalp movement when disturbed. Final day before death usually shows little to no movement whatsoever. This is definitely something that needs to be put out there to warn others, as I have lost several very rare and dear individuals to me from this, but now a damn near 7" young, healthy, AND gravid swammerdami was the last straw. I'm currently sterilizing any enclosures that had crickets and then rehousing any individual that was present in said containers, whether they consumed crickets or not. Luckily not all of my stock gets fed crickets, but I'm too paranoid about it now to not be overly cautious and protective.

 

[Delta9]

I'm so sorry for your loss, it's gut wrenching to have to watch it happen slowly like that when there is nothing you can do to help. This is exactly the same way the symptoms show up in the crickets, and almost exactly the same way it presented itself in my scorpions. With the scorpions, it would start by their tail going limp (common with other ailments as well, so not super indicative by that alone), followed by difficulty with locomotion, if any walking around at all, and very slow labored leg and pedipalp movement when disturbed. Final day before death usually shows little to no movement whatsoever. This is definitely something that needs to be put out there to warn others, as I have lost several very rare and dear individuals to me from this, but now a damn near 7" young, healthy, AND gravid swammerdami was the last straw. I'm currently sterilizing any enclosures that had crickets and then rehousing any individual that was present in said containers, whether they consumed crickets or not. Luckily not all of my stock gets fed crickets, but I'm too paranoid about it now to not be overly cautious and protective.

Thanks, it's a while back now but in hindsight this information would have really helped me back when I was dealing with it. I mentioned this to my friend today who works at a reptile/invert shop in the UK, and he mentioned that it's the 'acheta domestica' that normally carries the virus, and the other cricket species don't usually have it. He also mentioned that they managed to breed it out of their colony by raising the temps to 35 degrees C. I checked and it seems like the ones pet stores carry are the acheta domestica. So that sent me down a bit of a rabbit hole, I stumbled on this reddit post which mentions:

I'm not sure if they're aware of the densovirus in crickets, it's an airborne virus that specifically kills the particular species of crickets. The airborne virus is released from a dying crickets breath and that kills the rest of the colony. If you are wondering why they die so fast there you go.

Maybe someone can confirm/deny.

 

[MorbidArachnid]

Extremely sorry for your loss, that's devastating. I def think there's decent evidence that pet store crickets can carry something or have some ill effects in inverts, I've heard similar things about mantises and centipedes. I don't know exactly what it is though or what causes it, home raised crickets don't seem to have this problem, so I suspect some combination of malnutrition, crowding stress, and low temperatures makes them susceptible to disease.

CrPV right now only affects Acheta domesticus yea, which is why people switched to other species. I find it doubtful that this specific virus could affect arachnids when even other crickets are resistant to it, and that would be hard to prove without a lab. If you are getting crickets directly from the pet store and feeding them off though could be another related disease, Rickettsiella infects and is fatal to scorpions and can be carried by other insects.

https://journals.sagepub.com/doi/10.1177/0300985820951495?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

This article on a Rickettsiella infection in Emperor scorpions also suspected it came from feeder crickets, though they didn't find evidence of it in the crickets they examined.

It's also important to note that back leg dragging, twitching, ect are just evidence of sick and dying crickets, not of this specific virus. Crickets seem to need a lot to be able to properly use their back legs, so when weak or dying they'll drag their back legs even when not infected. You can see this if you've ever partially crushed their heads before feeding. It's akin to scorpion tail dragging.

Agree that keeping them warmer seems to improve their health, also obviously it's much better to breed them yourself to manage disease.