We have the odd outbreak of annoying pests in our house that disrupts the peace and tranquillity of our Rainforest/Desert...
Whitefly
By far the most terrible one we have to deal with is whitefly, which keep reappearing in plague proportions (and has lead to some mass plant culls in the past); as soon as we see these blighters these days out comes the bug spray... A couple of weekly treatments in a row seems to calm the outbreak.
Red spider mite
The balcony gets quite hot and dry - ideal conditions for red spider mite, which we have a bit of an outbreak of at the moment. Currently trying Ludwig's Rose Spider Mite (Etoxazole) as a method of control.
Fungal diseases
With Disas, fungi are an ever-present threat. We're currently in the process of losing one of our Disas to some sort of rot; we're going to try repotting it tonight as a last ditch rescue effort. :( I suspect the two day car trip home and high temperatures when we arrived back made it sad (the others seem OK so far).
Aphids
I've seen both blackfly and greenfly on the balcony; a quick round of Efekto's Garden Gun sees them off quite quickly.
If anyone knows of a source of biological control agents in South Africa for Whitefly and Red Spider Mite, I'm keen to get some!