All you need to know about mites

boina

boina

Lady of the mites
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Mites are one of the big topics that turn up over and over again. I can't count how often I've posted about them and tried to put a rational view on some rather phobic reactions. So, here is a consolidated post with everything about mites that I (and others) can link back to:

Mites are harmless – that needs to be said first.

The mites showing up again and again in tarantula enclosures or, more often, in feeder colonies, are grain mites and related groups (genus Acarus) - scavenger mites that live off rotting organic matter. They feed off anything they can find, including spider poop, boli, and, if things get bad, even rotting coco fibers. As such they are actually beneficial – they help clean up the enclosures, the same way springtails do, but for some unexplained reasons springtails are loved whereas mites are considered the bad guys, very undeserved. Mites in small number are actually beneficial – no need to get rid of them.

But what about those mites that attach themselves to your tarantula, often sitting at the base of the chelicerae? Those are parasites, right? – Wrong.

When mites come upon bad times – little food, drought, overpopulation – they’ll want to emigrate. Unfortunately mites aren’t built for walking (longer distances) so they go looking for a convenient ‘bus’, something that can carry them far away. In that case your tarantula comes in handy. The mites, now called phoretic (‘hitchhiker’) mites, climb on board and find a place with softer skin to attach themselves with their mouth parts. Prime real estate is the area around the chelicerae because that area actually has food service: every time the tarantula eats the mites get to clean up afterwards, or even during feeding, and get dinner, too. They are kind of… ewww… but still harmless. They just sit there, they don’t suck hemolymph or anything else from the tarantula.

Still those phoretic mites are really kind of… ewww. Want to get rid of them? Don’t try to brush or rip them off. That can actually damage the exoskeleton of your tarantula since the mites have attached themselves securely. Instead do something counter-intuitive. Place a small peace or rotting organic matter (fruit, veggy, or a dead cricket, whatever, the mites are not picky) in with your tarantula. The mites will smell the food and leave their ‘bus’ to have dinner. Take the rotting whatever out after a few hours, preferably using a spoon, so that all mites feeding on their feast will be collected, too. Rinse and repeat.

The one problem about mites is that in favorable circumstances (moisture and plenty of food) they can explode in numbers. Within days they are everywhere, a moving avalanche of annoying little freeloaders looking for a good life. This situation actually happens very rarely in a tarantula enclosure since even a moist one usually does not contain enough food for a mite explosion but it does happen more often in feeder colonies. If it does happen in a tarantula enclosure it annoys not only you but even more the poor spider that cannot escape those millions of nuisances. The spider will stand on tiptoes, move a lot and scratch itself. Now what?

Step one: wipe everything wipe-able off, but use only water. Chemicals are a bigger danger for your tarantula than for the mites. Wait a few hours for the next wave of mites to arrive, rinse and repeat.

Step two: dry your tarantulas enclosure out and make sure to remove boli and anything rotting in there. If you have a mite explosion something has gone wrong in the first place. A well kept tarantula enclosure can and will support a mite population but its proliferation will be limited.

Step three: get springtails. They will compete with mites for resources and keep them in check.

So you want to prevent mites because you just don’t want phoretic mites on your T or a mite explosion in your enclosures? Bad news: you can’t. Mites are lightweight, small, and everywhere. They come in through the air. They will always come in through the air. Good news: they are harmless. I think I said that already. But what about sterilizing the substrate one way or other? That will kill any mites, right? Yes, it will, and it will kill anything else living in the substrate, too. The first thing to arrive on this wonderful, pristine substrate will have it all to itself – paradise. What do you want to bet that the first thing to arrive will be a mite? And if it isn’t a mite it’s a fungal spore. What do you like better?

But what about those real tarantula parasitic mites? Those do exist (from the mite family Laelapidae), but they are rare and scientific literature about them is even rarer. They do need to come from somewhere, though. Real parasites are specific, tarantula mites don’t come in on a cricket or any other feeder, they only come in on another tarantula and a wild caught one at that. As of yet, nobody has managed to breed those rare and exotic mites in captivity. Is your tarantula wild caught? If not it doesn’t have a parasitic mite. And if it is wild caught? Parasitic mites don’t sit around the chelicerae usually but attach themselves at the edge of the carapace. If you really manage to find one – admire it and marvel. It’s much rarer than your tarantula. And unless the spider has a whole bunch of them it’s not going to do much harm either, they don’t suck that much hemolymph. I have no clue how to get them off since no one I know, have ever talked to, or ever read about has ever been in the situation. Personally, I’d document everything about the mite(s) and write a scientific paper about it ;), like these people did.

For a mite researcher's take on this topic read this.
 
Last edited:
PidderPeets

PidderPeets

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You're the best! I'm saving this so I can just link this thread directly from you, since I basically just relay all the information you've provided me on them already :D
 
Venom1080

Venom1080

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4,599
We just need one giant thread compiled of these Mythbuster threads of yours. This and the slime mold one.
 
buzz182

buzz182

Arachnosquire
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May 31, 2018
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This is an ok guide I guess but if you could just do one on mould, best beginner tarantulas & what to do if my T hasn't eaten for 2 weeks you'll have 99% of questions covered ;);)
 
Scoly

Scoly

Arachnobaron
Joined
Dec 4, 2013
Messages
489
Great rational post!

However, I'm going to chime in with some thoughts relating to centipedes, because there are differences between them and tarantulas, and an increasing number of centipede owners (such as myself, and @Staehilomyces) have lost specimens in the presence of mite infestations, and are questioning whether mites are really as harmless as everyone says they are.

This is not to imply mites do cause these deaths (the simple truth is we do not know) but here are some thoughts and observations on the matter:
  1. There are often grain mite infestations around the head parts and under the first few tergites, which is to be expected as that's the only places the centipede can't reach with its mouthparts, but sometimes we don't see anything.
  2. The centipedes writhe and wriggle their heads, and scratch at it with their legs. They also often turn and nibble at parts of their body where no mites are visibly present. So either I don't see the mite, or there's something internal, or it's just what they do when they feel an itch.
  3. Many keepers have reported "shovelling" behaviour - whereby a centipede continually pushes its head into the substrate or against objects while walking. Some people say this is to try to itch to get rid of the mites. When I've observed this it seemed far more like a case of paralysis of the head which may or may not be mite-related. I've seen centipedes affected by the cold develop this, and more recently had one turn that way out of the blue and die the next day. More often it's an ongoing condition, often accompanied by mite problems, that eventually results in death.
  4. The mites come on in droves as the centipede starts to die - but a centipede is often long dead before it stops moving, as others have noted with the smell of decay, and as can be attested by the fact a decapitated centipede will go on running for quite some time. This supports the notion that mites are not a cause of death, but just show up in large numbers for what seems to be a long time before death (but actually isn't).
  5. In some cases, grain mite infestations cause no harm to the centipede, and just clear up. This would seem to support the notion that mites are not causing the death of the centipedes, or if they are, then centipedes only succumb under certain conditions (general health, temp, humidity etc...)
  6. The same conditions which lead to visible mite infestations could also be the cause for centipede's poor health, either directly, or by being favourable conditions for the pathogens which are actually attacking the centipede, in which case mites are a nice warning system.
  7. The prevailing opinion seems to be that mites do not harm centipedes, but I wonder if people say that because that's what they've heard from experienced keepers. Some of those then become experienced keepers themselves and spread the same incorrect information, which keeps everyone in mutual agreement that this is fact, and whenever someone claims to think that mites did it, they are told it's not, and out of respect for those more experienced, and out of shame at losing their best specimens, these people don't argue.
  8. I also wonder if this opinion is correct for tarantulas, but not for centipedes. Here are some differences which might explain why tarantulas don't succumb to mite infestations while centipedes do:
    1. Most tarantulas lay some webbing, which creates a barrier between them and the substrate, whereas centipedes live in direct contact with the substrate.
    2. A tarantula's point of contact with the ground is different, they often don't let their many bodies touch un-webbed substrate, meaning any parasite needs to climb up its legs, which it can easily groom if it sense something crawling.
    3. A tarantula's body is covered in hairs.
    4. A centipede's head parts may, just because of the shape of them, hoard more food detritus, or be harder to clean.
    5. Tarantulas feed entirely on other invertebrates (or at least can) which means it is possible to fulfil their dietary requirements in captivity. Centipedes can generally survive entirely on insects, but we don't know what else they eat in nature while they are underground or deep within rotting wood. It may be that they eat other animals like worms, or fungus, soil, plant material (which is documented - and not just in captivity) or maybe it's the water droplets they drink off the underside of rocks that contain minerals, who knows! So it may be that we are not meeting their full nutritional requirements (or this depends on what the feeders are fed, or what your water source is) and they are therefore more susceptible to succumbing to pathogens.
  9. I often notice discolouration in such centipedes, with antennae, legs and in particular maxillipeds losing colour and appearing more faded and translucent than in healthy specimens.
  10. I have also noticed some centipedes get what appears to be dried blood crusts around the head - often on the maxillipeds - and this appears to happen after periods of excessively high humidity. Perhaps this is fungus, perhaps this is something the body produces in response to a pathogen, mites or other. Because this happens under such conditions it's hard to tell if mites have anything to do with it.
 
boina

boina

Lady of the mites
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Scoly said:
Great rational post!

However, I'm going to chime in with some thoughts relating to centipedes, because there are differences between them and tarantulas, and an increasing number of centipede owners (such as myself, and @Staehilomyces) have lost specimens in the presence of mite infestations, and are questioning whether mites are really as harmless as everyone says they are.

This is not to imply mites do cause these deaths (the simple truth is we do not know) but here are some thoughts and observations on the matter:
  1. There are often grain mite infestations around the head parts and under the first few tergites, which is to be expected as that's the only places the centipede can't reach with its mouthparts, but sometimes we don't see anything.
  2. The centipedes writhe and wriggle their heads, and scratch at it with their legs. They also often turn and nibble at parts of their body where no mites are visibly present. So either I don't see the mite, or there's something internal, or it's just what they do when they feel an itch.
  3. Many keepers have reported "shovelling" behaviour - whereby a centipede continually pushes its head into the substrate or against objects while walking. Some people say this is to try to itch to get rid of the mites. When I've observed this it seemed far more like a case of paralysis of the head which may or may not be mite-related. I've seen centipedes affected by the cold develop this, and more recently had one turn that way out of the blue and die the next day. More often it's an ongoing condition, often accompanied by mite problems, that eventually results in death.
  4. The mites come on in droves as the centipede starts to die - but a centipede is often long dead before it stops moving, as others have noted with the smell of decay, and as can be attested by the fact a decapitated centipede will go on running for quite some time. This supports the notion that mites are not a cause of death, but just show up in large numbers for what seems to be a long time before death (but actually isn't).
  5. In some cases, grain mite infestations cause no harm to the centipede, and just clear up. This would seem to support the notion that mites are not causing the death of the centipedes, or if they are, then centipedes only succumb under certain conditions (general health, temp, humidity etc...)
  6. The same conditions which lead to visible mite infestations could also be the cause for centipede's poor health, either directly, or by being favourable conditions for the pathogens which are actually attacking the centipede, in which case mites are a nice warning system.
  7. The prevailing opinion seems to be that mites do not harm centipedes, but I wonder if people say that because that's what they've heard from experienced keepers. Some of those then become experienced keepers themselves and spread the same incorrect information, which keeps everyone in mutual agreement that this is fact, and whenever someone claims to think that mites did it, they are told it's not, and out of respect for those more experienced, and out of shame at losing their best specimens, these people don't argue.
  8. I also wonder if this opinion is correct for tarantulas, but not for centipedes. Here are some differences which might explain why tarantulas don't succumb to mite infestations while centipedes do:
    1. Most tarantulas lay some webbing, which creates a barrier between them and the substrate, whereas centipedes live in direct contact with the substrate.
    2. A tarantula's point of contact with the ground is different, they often don't let their many bodies touch un-webbed substrate, meaning any parasite needs to climb up its legs, which it can easily groom if it sense something crawling.
    3. A tarantula's body is covered in hairs.
    4. A centipede's head parts may, just because of the shape of them, hoard more food detritus, or be harder to clean.
    5. Tarantulas feed entirely on other invertebrates (or at least can) which means it is possible to fulfil their dietary requirements in captivity. Centipedes can generally survive entirely on insects, but we don't know what else they eat in nature while they are underground or deep within rotting wood. It may be that they eat other animals like worms, or fungus, soil, plant material (which is documented - and not just in captivity) or maybe it's the water droplets they drink off the underside of rocks that contain minerals, who knows! So it may be that we are not meeting their full nutritional requirements (or this depends on what the feeders are fed, or what your water source is) and they are therefore more susceptible to succumbing to pathogens.
  9. I often notice discolouration in such centipedes, with antennae, legs and in particular maxillipeds losing colour and appearing more faded and translucent than in healthy specimens.
  10. I have also noticed some centipedes get what appears to be dried blood crusts around the head - often on the maxillipeds - and this appears to happen after periods of excessively high humidity. Perhaps this is fungus, perhaps this is something the body produces in response to a pathogen, mites or other. Because this happens under such conditions it's hard to tell if mites have anything to do with it.
Click to expand...
You make some great points about centipedes but your knowledge about mite biology seems not quite as comprehensive. Let me restate this:

1. Mites are attracted to sick and dying animals because they are anticipating a big meal.
2. Mites find the moist living conditions of centipedes in plenty of decaying organic matter highly appealing - as do a plethora of potentially harmful, but invisible, bacteria.
3. Mites can and will roam all over a centipede and may certainly bother it - but they are NOT able to feed from its body.
4. I don't know if there are specific centipede parasites, but your average scavenger mite will NOT harm a centipede. The mite is simply not able to do so.

And I'm not saying that because someone (your 'experienced keeper') told me so but because I know about mite biology and parasites in general.
 
Scoly

Scoly

Arachnobaron
Joined
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Messages
489
boina said:
And I'm not saying that because someone (your 'experienced keeper') told me so but because I know about mite biology and parasites in general.
Click to expand...
And that's exactly why I wanted your view on these points :)

I was not suggesting that the mites feed off centipedes, just that their presence could be a contributing factor in other health problems, such as the spreading of fungal infections. However, I am happy to accept that a concentration of mites (with the exception of specialised parasites) are never a cause, although they are potentially a symptom of another problem - perhaps also a fungal infection?

We throw the word "mycosis" around quite a bit whenever a centipede get humidity related health problems, most commonly black markings on the head regions, but for all we know these could be bacterial infections rather than fungal. It may be that the mites are able to scent this and therefore congregate on those areas?

Have you any thoughts or knowledge on fungal infections in arthropods? And do you think some of the anti-fungal treatments available for humans might work, or are these overly toxic?
 
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