there are mites housing on my plants and in the soil of which I´m not aware whether they are pests or predators or whatever. There is no picture in the internet which shows this special mite - at least Google doesn´t find the exact one which may be because I don´t know the name of this special mate.
I have spend SOME time observing them below an 8-time magnifier. Finally I have drawn this creature and perhaps here´s someone who identifies this chap.
First: Compared to typical spider mites this species is approx. twice as large. You can easily watch them moving around with the naked eye. The body is less than 1 mm in length (the legs not included) and I can only guess it must be around 0,7 mm in length. The body of the adults is almost completely black or reddish-black. The mouthparts and the legs are light-coloured - yellowish-white to white-ochre.
The most noticable character are the very long front legs. The typical spider mites don´t have such extended front legs. The body of the adults is comparatively flat, not that spherical than of spider mites. Whereas the juveniles do have a spherical body and have a brilliant red, semi-translucent body.
I can watch these buddies occasionally on almost all of my plants - also on carnivores. They run mostly relatively quick - which is atypical for spider mites. And talking about spider mites: These blackish mites don´t seem to spin threads. They obviously don´t harm CPs. If they harm my Lithops and other Mesembs I don´t know! Mite damage is hardly spottable on Lithops (until it´s too late)! Faucaria and Titanopsis show brown spots on their leaves. However as these often attract typical spider mites, these damages may result from spider mites!
The mites I´m talking about here appear numerously after a heavy watering of the soil of my Lithops etc.! Then you can watch them running thrilled (panicked?) all over the substrate and also over the plants.
If I see them on the soil or on plants they usually move quickly. Only very few times I watched them moving slowly over a leaf. Not long ago one specimen walked comfortably on a Faucaria leaf, seemingly observing the surface of the leaf. My magnifier is of course too weak to recognise if a mite, an aphid or similar stitches into the leaf. ;-) Some years ago I spotted a lot of these mites on a Heliamphora hybrid. Most of the adults had very thin, broken streaks on the back - one longitudinal and one latitudinal - resembling a cross similar to that of a cross spider. The current mites don´t show this characteristic.
In case they are pests the worst fact about them is: They are resistent against acaricides and against some pesticides. They have survived treatments with Kiron, Kanemite, Dimethoat and Thiacloprid! The ones settled the Heli hybrid have been killed by Imidacloprid (Lizetan spray).
I have some hope that these mites are perhaps predators! That would be great!
By the way: I rarely notice the juveniles on my Lithops and Co.! They seem to have a good hideaway. The juveniles always move slowly and that is somehow worrying!
So, this is all information I can tell you about these acari. I hope here´s someone who can identify the species and can tell me if they are harmful or harmless and what to do if they are pests!
Thank you very much.
PS: As for some details on the drawing I have orientated myself by a drawing of a grass mite --> http://www.gesundhei...e/grasmilbe.jpg ! Of course you cannot recognise single segments of a leg under an 8-time magnifier!
EDITED: Further research has resulted that this mysterious mite is most likely a Bryobia species - perhaps Bryobia praetiosa!
For comparison: http://entnemdept.uf...over_mite01.jpg
Edited by Andreas Eils, 02 July 2012 - 23:43 PM.