White fungus on cacti?

[lowrie333]

I have several cacti at home in varoius places in bright sunlight and some in more shady conditions. I have grown cacti for years and have never come across this. I have a white furry looking fungus growing on one of my cacti. I had kept the fungus confined to one room but now it seems to have infected the rest of my collection and looks as though it is now infecting my oldest plant. You can wash the fungus off, but it comes back, and if left eventually kills the plant. Does anyone have any ideas about what this is and if there is anything i can use to get rid of it before it kills my 30 year cacti.

[jimbouk]

I hada similar problem - apparently it is an infectious fungus that spreads to neighbouring plants quite easily. I tried washing off but it came back so had to resort to a mild fungal spray treatment for a few weeks. Try: http://www.suite101.com/article.cfm/5400/34942 fo
r further info.

[lowrie333]

thanks for that - did you have the same problem on cacti or other plants? I am a bit hesitant to use chemicals on cacti as i have had bad experiences before.

[Cactus]

As you can probably guess by my screen-name, cacti are a particular specialist subject of mine. It sounds like you've got an infestation of Mealy Bugs, they're like minute greyish white woodlice and the white fluffy stuff are their nests. The only thing to do is isolate the infected plants to a windowsill with no healthy plants on it, remove the bulk of the nests/eggs/any visible bugs with a cotton bud or similar soft implement, even checking below the soil or grit line around the base of the plant ;the little b*ggers can nest underground. Finally, treat with a systemic insecticide that claims to kill aphids (greenfly) but can be used on indoor plants. (systemic being one that is sprayed or watered on to be drawn up internally by the roots) Repeat this process as necessary to keep them under control. I say "under control" as they are faily hardy and difficult to kill without harming the plant with too higher dosage of insecticide. They also evolve and become tolerent to the various types of insecticide, they really are a pain to get rid of completely. I hope this has been of help to you, and i hope you get the infestation under control. Regards, Cactus.