Spider Death and Dyskinetic Syndrome

[MattjediEdmonds]

I want to post some information of the death of a sling and update the info. as I get any.
I bought a 2nd instar Brachypelma emilia in January of 2018. He seemed to be thriving. He molted 4 times and was a prolific burrower and eater. He seemed the picture of health until one day he was shuffling and spasming in what others have described as DKS. 2 days later he was dead on his back.
I'm a bug lover in general and I know they parasitize each other constantly, so I didn't throw away the body. In fact I just set the cube on a shelf in my office to watch and see if anything emerged. Sure enough 20 days later (I haven't been checking daily, but about twice a week) there are a dozen scuttle flies in the cube. They are too large to escape through the ventilation which makes me pretty sure they didn't get in after the sling died.
My two guesses at this moment are 1) they came with the sling from the breeder (from an infected breeder tank) and were harmlessly living off the spider until it died and then pupated, or 2) they came with the sling from the breeder and killed the spider causing the symptoms of DKS as they ate him from the inside as maggots.
I'm making inquiries to entomologists and appreciate any help with contacts and I will report anything I find out. Attached are the sling at his burrow, and one of the scuttle flies that were found in his cube.

 

[chanda]

My two guesses at this moment are 1) they came with the sling from the breeder (from an infected breeder tank) and were harmlessly living off the spider until it died and then pupated, or 2) they came with the sling from the breeder and killed the spider causing the symptoms of DKS as they ate him from the inside as maggots.
I'm making inquiries to entomologists and appreciate any help with contacts and I will report anything I find out. Attached are the sling at his burrow, and one of the scuttle flies that were found in his cube. View attachment 288842 View attachment 288844 View attachment 288845

The life cycle of phorid flies is pretty quick. Given that the spider in question molted four times while in your care, the maggots were not inside that spider the entire time. While it is possible that phorid flies were transported with the spider from the breeder, it is just as likely that they were already present at your place and got into the tank at a later time. They are small, fast, and remarkably resourceful. They can slip into a tank when you open it for feeding, watering, or cleaning. They can hitch a ride with feeder crickets or roaches. They are very fast to discover and infest any dead or dying feeders or pets and will seek them out to lay eggs on them. They can even lay their eggs right through the small ventilation holes or insect screen tops of fruit fly cups. I am constantly battling phorid flies in my bug and reptile room, and if I make the mistake of leaving a closed fruit fly culture in the room overnight, I will almost certainly find it full of phorid flies (which will outcompete and displace the fruit flies) very quickly.

As far as whether the maggots were what killed the spider, I couldn't say for sure - but it's certainly a possibility, particularly if it suffered any sort of injury. I lost a P. irminia sling to phorid flies, following a bad molt - the spider lost a couple of legs in the molt, and (as near as I can tell) the flies laid eggs in the stumps, allowing the maggots to begin eating the spider from the inside. When she died, I wanted to pose and dry her for mounting, but discovered that she was absolutely riddled with maggots - and this was only a day or two after dying.

I've also had a couple of Hercules beetles (Dynastes grantii) that became infested with phorid flies while still living. I believe they may have suffered punctures from the horns of other males in the tank, because there was a small hole in the underside of each of the beetles - and phorid flies were emerging from the hole. When I looked closely, there were also tiny maggots present - but the beetles were still walking around (for another day or two).

In your case, though, you said you spotted the flies 20 days after the spider died? That sounds more like opportunistic egg laying on an already-dead spider, because if the maggots had been what killed the spider, I'd have expected the flies to have emerged much sooner!

*Edited to add: Is it possible the spider might have accidentally been exposed to some sort of chemicals? Maybe something on your hands when you were feeding/tending him, or something that was sprayed in or near your home or outside your windows, air vents, or the air intakes for your heating or cooling system?

 

[MattjediEdmonds]

Hi Chanda,
Thanks for the reply and info.!
My guess is that they came in on a feeder and got into the sling when it molted a few days before it showed signs of distress. I know coincidences can trick the brain, but it's hard to imagine the death and flies aren't related... although I try to keep an open mind.

 

[chanda]

Hi Chanda,
Thanks for the reply and info.!
My guess is that they came in on a feeder and got into the sling when it molted a few days before it showed signs of distress. I know coincidences can trick the brain, but it's hard to imagine the death and flies aren't related... although I try to keep an open mind.

In my experience, where there are dead bugs of any sort, there are always flies. They are highly opportunistic and extremely sensitive to the scent of death, long before it becomes apparent to us. While it's possible that they were connected to the spider's death, it is equally likely that they were merely taking advantage of a newly-dead creature. Based on the average life-cycle of a phorid fly (between 11 and 21 days from egg to adult) seeing adults roughly 20 days after death fits with eggs laid on an already-dead spider.

 

[The Grym Reaper]

shuffling and spasming in what others have described as DKS

When people say "DKS/Dyskinetic Syndrome" they actually mean "dyskinesia". This isn't actually a disease in of itself but a symptom that usually arises as a result of poisoning/internal parasite/impaction/extreme dehydration.

That said, it would seem that the spider died (I'd rule out internal parasite with them being CB slings) and then became an egg-laying medium for the flies.