Oct 212015

Hello again with another mount from the collection of MNHN in Paris. The shown slide has the following references :

  • Name of species : Axonopsis romijni (no longer valid at present)
  • Locality : lake “du grand Laoucien” in France
  • Date of collection : 1927
  • Reference of slide : 19C4
  • Collection : C.M. (Understand C. Motas)
  • Sex : male

It is a real pitty that the medium used for the mount is nearly never indicated. In this case it is pretty well preserved for a mount done in 1927.

According to A Checklist of the water mites of France(Acari: Hydrachnidia) of Harry SMIT and Reinhard GERECKE, this species is present in France in Ardèche, in Pyrénées-Orientales and in Var. It is a member of Aturidae family ad Aturinae subfamily.

I wonder what is the origin of Axonopsis name ? This could be due to the fact that Axonopsis has a dark spot (like an eye “ops”) in the axis (“axo”) of the animal ? Your opinion is welcome.


The exact naming of the species was recently Axonopsis (Hexaxonopsis) romijni Viets, 1923 (same reference as here under published in 2010), but according to this recent publication (2015) :

Revision of the status of some genus-level water mite taxa in the families Pionidae Thor, 1900, Aturidae Thor, 1900, and Nudomideopsidae Smith, 1990 (Acari: Hydrachnidiae) – IAN M. SMITH, DAVID R. COOK & REINHARD GERECKE

We are proposing here that a number of taxa in the families Pionidae, Aturidae (subfamilies Axonopsinae and Aturinae), and Nudomideopsidae that have been treated as subgenera in the recent literature should be elevated to full generic rank to reflect the diversity, morphological distinctness, relationships, and apparent ages of the species groups they comprise.

… the name of the species has been moved to Paraxonopsis romijni. Paraxonopsis is elevated in
rank from subgenera to full genera, and the former sub-genera seems to have changed by the way…

More information on the site of collection here. C. Motas studied the fauna of this lake and published the following book : Contribution à la connaissance des hydracariens français particulièrement du Sud-Est de la France, C. Motas, Travaux du Laboratoire d’Hydrobiologie et de Pisciculture de l’Université de Grenoble, 1928″.

In the title of this article, I mention probable parasite of chironomids, because it seems to be an accepted hypothesis unless there is no real proof of evidence of that. Parasitism on chironomids is probable, as many related genera include chironomid-parasitic species. In all known cases, it is the larva that parasitizes the insect host. This subject is still to be studied !

Here is a link of one of my colleagues with a live image of an Aturidae.

For this post, my thanks goes to Professor Gerecke and MNHN, Paris.

Jul 282015

Hello world ! I am the first surprised to publish photos of an Hydrachnidia. A colleague, on a French forum on insects, sent me some samples of water mite larvae collected on the Irish damselfly (Coenagrion lunulatum in the family of Coenagrionidae), in the French vulcan park in the very center of France.

We made a microscopic mount and some photos of a non gorged larva. We are happy to share the result with you.

I warmly thank Reinhard Gerecke, Andrzej Zawal & Peter Martin for their friendly help for proposing the Arrenurus genera for this mite.

The possible species are Arrenurus bicuspidator, Arrenurus tetracyphus, or another not larva described species.

At this stage, Coenagrion lunulatum species is not yet known as Arrenurus host.

More information will follow if I get some.

Thanks for your comments if any.


Jul 062015

If you are interested in honey bees or mites you probably have heard about this pest ! Varroa destructor sounds like a horrible monster, a sort of Terminator of our familiar honey bees. But this pest exists from ages. It is true that human activities has spead this pest all over the world, probably except Australia and Man Island (why ?), but I express some doubts about the fact that they are responsible of colony collapse disaster. A factor ? Maybe one factor among many other stronger factors like neonicotinoids ?

This is a sentitive question, my purpose here is only to show you two examples of this pest, show you the hidden beauty of this obese mite !

For years, among naturalists, there have been confusion between Varroa destructor and Varroa jacobsoni, it seems that the confusion is now over, and the common species we find in our European hives is Varroa destructor. Anderson & Trueman clarified the classification in a famous study. You will find plenty of publications on this subject on the internet.

If you happen to find fresh such mites, send us some examplaries in alcool, we will be happy to inspect, determine, and make some new photographies.


Currently identified species of Varroa :

  • Varroa destructor Anderson & Trueman, 2000 is a virulent parasite that infests its natural host, Apis mellifera (western honey bee) worldwide and Apis cerana (Asian honey bees).
  • Varroa jacobsoni Oudemans, 1904 is a relatively benign parasite of Apis cerana.
  • Varroa rindereri de Guzman & Delfinado-Baker, 1996
  • Varroa sinhai (Delfinado & Baker, 1974)
  • Varroa wongsirii (Lekprayoon & Tangkanasing, 1991)
May 192015
Chaetodactylus osmiae - parasite of Mason bee

Hello friends, This is a pest of different species of Mason bee (Osmia) in Europe. I am sure there are other species of Chaetodactylidae in Europe, but for the time being I found only this one. I made a photo in light microscopy of the whole acari, a detail of the dorsal cuticule, and a […]