3 replies to this topic

[dspdrew]

There is a big difference between parasitic mites and phoretic mites living on ants or other invertebrates. Since I can't ID most of the mites I see, does anyone know how tell the difference?

 

Two times I have witnessed mites on ants that were parasitic with certainty.

 

One time it was a bunch of Myrmecocystus testaceus I caught. These mites clearly had their heads bored into the ants in soft areas between the pieces of their exoskeleton.

 

 

 

It was pretty obvious that these were parasitic, so I removed them as best I could with the tools I had at the time.

 

Another time it was an entire colony of Pheidole megacephala. These were given to me, and were eventually discovered to be completely covered in mites. The ants were dying left and right and in a way that made it fairly obvious that it was the mites that were killing them.

 

 

 

Now these mites were so big compared to the ants, and there were so many of them, that they pretty much covered the ants completely and therefor I can't tell exactly where or how they are feeding on the ants, but it could have certainly been at the joints of their exoskeleton or any soft spots they can get to.

 

A while back I found mites all over some Veromessor pergandei queens I found.

 

 

 

While it might look like they are in the joints of the ant's exoskeleton, most weren't and the ones that were, were actually facing out so their heads were not in the joint. I could never find any that looked like they were actually feeding on the ant's hemolymph, so I could never say for sure that these were parasitic. I think it was likely that they were just phoretic. I killed them all and removed them anyways just to be safe.

 

I have now found some extremely tiny mites on my Dolopomyrmex queens, and I'm a little worried now since they are of my only remaining Dolopomyrmex queens, and even have developing brood. These mites, like the ones that were on the Veromessor pergandei don't seem to be feeding on any soft areas of the ant.

 

I'm only assuming these mites can only feed on the ant's hemolymph though the soft areas between the plates of their exoskeletons, which brings me back to my original question. How can I tell whether or not a mite is parasitic by looking at their behavior? Is it possible for these mites to be feeding on the ant right through their exoskeleton? Could they be feeding on their hemolymph for a while, and then be taking a break and moving around?

 

Also, if anyone knows of any material I can read that talks specifically about parasitic mites and exactly how they feed on their host, I would love to read it. I searched around for a while, but could only find very general information about parasitic mites.

[drtrmiller]

The $150 book I bought goes into the subject in some detail.  From skimming, I learned that a well-adapted parasitic mite will not kill its host.  The very worst parasitic mites, as they relate to ants, do feed from the ants—the ants don't react to the mites because of "tasty secretions" that the mites produce—but as long as the colony is generally healthy, otherwise, the presence of a small number of mites should not mean colony collapse.

 

One way mites can be detrimental is when they group together in hoards and hinder the movement of the insect.  That, from what I read, is very bad.  Some mites also position themselves around the mouth of ants and inhibit trophallaxis.  Other mites are particularly well adapted, and actually mimic certain body parts of their hosts, such as Macrocheles rettenmeyeri, which inserts its mouthpart into the hind leg of a particular army ants, and in doing so, becomes the ant's functional "claw."

 

Mites are extremely frequently found cohabiting with ants in nature, and one of the most attractive genera to mites, is, strangely enough, Lasius.

 

Like I said, I just barely briefly skimmed a few relevant sections from the book, and I don't even remember everything I read, the writing was so taxonomically and anatomically dense.

 

Mites: Ecology, Evolution and Behaviour (David Walter | Heather Proctor)

Edited by drtrmiller, April 16 2015 - 8:07 AM.

[dspdrew]

Thanks. I was wondering if that mite book you were raving about would have some of the information I was looking for.

[Myrmicinae]

Mites are extremely frequently found cohabiting with ants in nature, and one of the most attractive genera to mites, is, strangely enough, Lasius.

 

I think that Myrmica is another particularly unfortunate genus, as far as mite parasitism goes.