7 replies to this topic

[noebl1]

This Spring I created a simple outworld design where I pour abut .25" of hydrostone into a container, and put in notches for test tubes.  In the back there's a hole with a mesh screen for ventilation.  I use this set up for a lot of my ant colonies that are small.

 

This week the colony in there, a 2016 Tetramorium queen, died with no worker deaths at all, so figured possibly something wrong with her as she had been acting strange for a day or so prior to death. I froze the entire box to kill the brood, and removed them, and wiped the hydrostone and insides of the box with rubbing alcohol in a cotton ball.  That was maybe 3 days ago, and it's been sitting open to vent any remaining alcohol.

 

So today I printed some new end caps from TPU for the test tubes, again something I have done before, with the same filament.  I haven't had any problems:

 

I added some coconut fiber and reptile sand to the outworld (again stuff I've been using for awhile), and added 2 fresh test tube setups (water/cotton) with the end caps on them.   I had a small Lasius alienus colony from last Fall that had several workers eclose, so went to use this setup.  I removed the cotton ball blocking their test tube, and inserted the filament cap, and placed it in the out world.

 

Fast forward a few hours, I go to check on them, all the workers are curled up, and the queen is alive, but obviously stressed out.  I removed the test tube from the outworld, capped it off with a cotton ball, and some of the workers are now twitching and showing signs of life (though not sure if they're going to make it.)  I'm trying to figure out the source of the toxin that killed them to avoid this in the future.

• Rubbing alcohol still gassing from the hydrostone (though no smell of it)?
• TPU filament end cap gassing something as freshly printed?
• Something else?

 

I'm leaning on the TPU filament as it was relatively freshly printed (maybe 20-30mins before adding it the test tube.) It's something I've already used successfully with my recent Aphaenogaster and Myrmica colonies, however the prints were at least a few days old before adding them to the test tubes, so not fresh off the printer.

 

Thanks!

[YsTheAnt]

There could be some alcohol residue in the hydrostone, as it's super absorbent. To be safe, I would rinse out the entire container and dry. Let the filament age a bit, and then try it on a few workers. Or, try rinsing and drying then putting the fresh flilament in to see if that's killing them. If not, it's alcohol in the hydrostone, so just rinse out.

If you want to be safe, just age the filament and rinse out, you should be good.

[drtrmiller]

Firstly, ensure your ants have access to unchlorinated, clean drinking water.  Dehydrated ants frequently show the same symptoms as those which have been exposed to pesticides.  And what about humidity?  Is the air very dry in your home?  In certain situations, this may cause problems for ants even if they have a source of drinking water.

 

While applying isopropyl alcohol to the enclosure was likely an unnecessary cleaning step, it is not cause for concern unless the absorbent stone was left to soak for long periods and the enclosure was poorly ventilated.  I'm not even sure how far into the stone the huge alcohol molecules would be able to penetrate (probably not very far).  "Reptile sand" could composed of calcium, which could potentially be an issue, but I'm just speculating.  Also, remember when Tar Heel Ants mentioned inadvertently using some toxic stone material for casting their products, just by switching suppliers?  It is possible some vendors use different compositions than others, and the Hydrostone you're using could be an issue, if it's a supplier that you've never used before.

 

Here are the components you mentioned:

• Plastic box
• TPU (thermoplastic polyurethane) filament
• Isopropyl alcohol
• Cotton ball
• Glass test tube
• Water
• "Coconut fiber"
• "Reptile sand"
• "Hydrostone"

That's a lot of variables, but none of them stand out as posing any problem whatsoever.  Smaller ants tend to succumb to toxins more quickly and with less concentration required for a lethal dose.  Toxicity studies are expressed in terms like LD₅₀, which is It is the amount of the substance required (usually per body weight) to kill 50% of the test population, so the Tetramorium queen death could be a fluke, unless the queen was already in poor health.

 

If you're serious about testing for toxins or poisons, you would need to isolate your variables.  In my past studies on casting resin toxicity, I have taken healthy ants and introduced them to small samples of a test substance in a small, confined space, in configurations where the ants contacted the substance, and in other configurations where they did not contact the substance, but were kept in close proximity to it.

 

Start by investigating the obvious environmental questions of drinking water and humidity, and then establish a method for independently testing each of the variables in your setup.  If any of these are responsible for your unexplained deaths, this method will undoubtedly reveal the culprit.  If not, then at least you can exclude them, and have learned something all the same.

Edited by drtrmiller, May 27 2018 - 3:31 AM.

[noebl1]

Thank you for the replies.  @DrTmiller definitely really appreciate the insights too.

 

Here's some better details I think, especially if any one searches for this later:

• Enclosure - BoxBox container from The Container Store, made from "food-safe polystyrene", item 10051084  
• TPU (thermoplastic polyurethane) filament - Unfortunately details unknown as Yoyi's site except "MSDS available", but no links (may need to request), UPC 749110382025 on Amazon
• Water - well water, no chlorine in water tests done 
• Isopropyl alcohol 70% - CVS brand
• Coconut fiber - Zoo Med Eco Earth Loose Coconut Fiber Substrate, ASIN: B00167VVP4
• Sand - Fluker's Natural Reptile Sand Bedding, ASIN: B01HO27ZHW
• Hydrostone - Plaster Guys, Ebay (Link Drew posted awhile ago for his source)
• Cotton balls -Classic Cotton Balls Jumbo Size, 100% cotton, CVS brand, ASIN: B000VUV9QI
• Glass Test tubes - Greenwood Products GS1517 Culture Tube, Borosilicate Glass, Part Number GS1517

 

Part of how I jumped to the conclusion I did, was the boxes, cotton balls, test tubes, coconut fiber, reptile sand, and hydrostone are all things I've been using for the last 1-3 years without the problem I saw yesterday.  The water is the same, but being a well, there is definitely variability to the water contents based on time of year, well water level, sediment that may be pulled up, etc.  I did not observe them leaving their test tube, which is the same glass test tube with water they had been contained with since Sept 2017.  However I did not observe them all day to see if they had left and gone into the other test tubes.

 

The access to water and/or humidity really intrigues me and never crossed my mind. According to the logs I looked at from yesterday, the humidity was 45% when I added them to the out world, and dropped to 34% when I noticed them having problems last night (not sure when the problems started).  The temperature was 85F when I added them, and 78F when the problems were observed.  These measurements were taken from a Davis weather station console located about 6' away, so probably reasonable accurate.  Though makes me realize I'm not capturing the output from the ant cabinet's temperature and database into my database for charting later.  (TL;DR I push a lot of sensor data thru MQTT and have a database that monitors it so I can chart it (or create alarms, etc), but not all my sensors yet push to MQTT.) Their test tube still contained water, though it is starting to get low.  Being I removed the cotton ball and placed the end cap on it, the humidity would have dropped as the end cap does contain an opening for them to pass thru (about 5mm in diameter.)

 

I remember a bit more details on the end caps as well. I printed the end caps (already being used in other colonies), at least a week, if not more, before adding them to a test tube with live ants within them.  Yesterday was a distinct difference where the printer finished, I cleaned off the prints, and inserted them into the test tubes within 30mins (if not less) of them completing printing.  They were warm-cool to the touch on their exterior, but unsure if interior was cool.  I typically don't immediately print anything and expose ants to it.

 

It's good to know cleaning with Isopropyl alcohol is unnecessary, will avoid this step in the future.

 

So to me, two probable variables to investigate right now would be:

• Humidity level - Dramatic drop in humidity levels?
• Potential exposure to TPU filament fresh off the printer?

I checked on them this am, and a couple of the workers appear to have recovered; it's current state is they have the cotton ball back at the end.  However no care being taken of the brood (not sure if it's still alive either.)

 

I have several Lasius queens I caught this Fall, I may try to isolate some of the variables as you suggest to see if I can narrow this down to try to avoid whatever happened again.  Though not easy to replicate a potential humidity shock/drop scenario.

[Enderz]

I think that it may have been the 3d printed items, as you didn't specify if you washed them or let them air out or something.

[noebl1]

I think that it may have been the 3d printed items, as you didn't specify if you washed them or let them air out or something.

 

I did not wash or let them air out, that's 100% correct.  I usually don't wash them off, but also typically don't expose the ants immediately.  TPU is also new for me to use, prior I was printing mainly PLA.

Edited by noebl1, May 27 2018 - 10:54 AM.

[drtrmiller]

I have used a few different flexible TPU filaments to fabricate test tube inserts for the past 18 months or so, and have not experienced any issues.  Luckily, it would be very easy for you to test this.  I think you will figure it out if you conduct your investigation methodically.

[noebl1]

I have used a few different flexible TPU filaments to fabricate test tube inserts for the past 18 months or so, and have not experienced any issues.  Luckily, it would be very easy for you to test this.  I think you will figure it out if you conduct your investigation methodically.

 

Thank you, I will definitely try this out to test once I have enough Lasius queens with workers.