red spider

[Carlo & Daniele]

we sometimes have problems with red spider, if we are not in time we cut all the damaged heads, new and sane ones sprout soon

[andrea.a]

In My Experience, daily light moisturings are really good to prevent this Little bug.
Andrea.

[Carlo & Daniele]

yes we heard the same! btw the problem is only on few plants for the moment

[Simon]

I deal with them by spraying the plants with a fairly strong jet of water straight out of the hose, i do it a few times about two to three weeks apart in spring. If that fails I have had pretty good results with Eco Oil a botanical oil product available here. Warning if using botanical oils test on each species first before spraying the whole lot(they can burn plants especial Strombocactus and T. alonsoii). Another issue with mite is that they infest some cultivars like fukuryu when they don't seem to be a problem on the species Myriostigma. Also they seem to often be worse on plants that are grafted than they are on the same species when grown own roots. In recent years I have had predator mites build up numbers and they control  them pretty well except in early spring when the pest mites are more active than the predators. One last bit of info....I believe the  mites we have problems with are actually False Spider Mites from the genus Brevipalpus. There is a species of these Brevipalpus russulus, that is specific to cacti.