Dealing with a Phorid Fly Invasion?

[Caemoxie]

Hello all. Just wanted to put this out there for additional feedback and for reference for others as I had difficulty finding concrete information when I started noticing a real problem.

Context:
Over the last 3 months or so I began to notice a real increase in sling deaths in my collection of ~170 Ts. At first I wasn't too alarmed, they deaths were fairly spaced out (at first) and frankly, slings just die sometimes. The majority appeared to be thriving, so I was a bit sad about it and moved on. I also noticed an increase of fruit flies in the spider room at this time and shrugged that off as well. This is by far the largest collection I've ever attempted to maintain and detrivores are expected and unavoidable. I also began to notice small larva feeding on the corpses of my slings, but again I chalked this up to harmless detrivore activity and moved on. Once I hit about 15 dead slings in 2 months, I decided there had to be a problem, either in my husbandry or some external force. Tried a few things, raising temps, increasing humidity, so on. None of which helped and slings continued to die seemingly at random, from all different habitats and species. Finally I lost 2 adults, a pair of mature male OBTs, one covered in larvae and the other surrounded by 'fruit flies', a bit more internet research later and I concluded that my fruit flies were phorid flies and some anecdotal accounts that they and there larvae can be a threat to Ts.

Conclusion:
Somewhat desperately and with no other leads to explain my, now, 20 dead slings, 2 dead adults, and 1 juvenile over 3 months, I decided that either the phorid flies or just insanely bad luck is the culprit of my woes. So. I thus began the extensive work changing the substrate of every spider I own, checking them for infestation, starting a springtail and isopod culture, getting a light based fly killer, and generally cleaning EVERYTHING. My hope is that some combination of these measures will solve my problem. However, I only came here to post because I feel I've gotten my first hard evidence that an external attacker is the source of my problem. My juvenile Omothymus violaceopes lightly spattered with injuries across its abdomen (pics attached along with a pic of one of my, hopefully correctly identified, phorid fly culprits). The spider does not appear to be infested any more and its wounds are closed so I do not believe it specifically is any immediate danger.

I am hoping that this tale will be helpful to anyone else in a similar situation in the future, given my own research woes. And any thoughts on my conclusions or solutions is welcome. Apologies in advance for the quality of the photos.

 

[l4nsky]

With any large collection, if you're not practicing active pest management, then you'll inevitably be practicing reactive pest management on a long enough time frame. Sounds like you learned the hard way with some losses, my condolences.

IME, phorid fly outbreaks tend to start in the feeder colonies and disperse from there. For this reason, I have both my lateralis and dubia colonies under the UV light traps. I also keep these bare bottom and clean weekly to remove the rotting carcasses that fuel the phorid population. Beyond that, I may find one or two pupae on an uneaten feeder from time to time, but I just remove the mess and squish the pupae as I see them.

 

[Kada]

With any large collection, if you're not practicing active pest management, then you'll inevitably be practicing reactive pest management on a long enough time frame. Sounds like you learned the hard way with some losses, my condolences.

IME, phorid fly outbreaks tend to start in the feeder colonies and disperse from there. For this reason, I have both my lateralis and dubia colonies under the UV light traps. I also keep these bare bottom and clean weekly to remove the rotting carcasses that fuel the phorid population. Beyond that, I may find one or two pupae on an uneaten feeder from time to time, but I just remove the mess and squish the pupae as I see them.

Hadn't thought of a uv option around feeder colonies. Keeping the feeders protected from, but surrounded by, the UV is a brilliant idea!

 

[Wolfram1]

i would recommend using phorid-fly proof containers, but i realize this may not be doable at this point, or at least not without herculean effort

personally i use 0.2mm stainless steel gauze melted into the plastic covering over the ventilation openings to achieve this, but the UV may also be an option, if an imperfect one

i don't have to worry about any phorid flies gaining access to any of my slings

here is a post of mine that references the material https://arachnoboards.com/threads/habitat-advice.349117/post-3222761

keeping the feeders thus secured may be the easier solution, if they are in a fly proof container the pests won't get in or out either way



@l4nsky, there is also this 0.1mm version, smooth like silk, handles more like a fabric than steel, maybe something to up your game

 

[Brewser]

UV Lighted Wall Sconce with Sticky Board Trap

 

[l4nsky]

@l4nsky, there is also this 0.1mm version, smooth like silk, handles more like a fabric than steel, maybe something to up your game

I think I'll leave that level of meticulous to you lol (0.1mm is RIDICULOUSLY small). I think that ship has already sailed for me lol. I'll likely always have phorid flies in my facility as they're almost impossible to exterminate once established in a feeder colony, especially as large as mine are. Actively managing the population as described above does keep them reasonable and a non-issue really.