Plants have defense systems of their own. However, when grown in large numbers
indoors and when the plants are grown in less-than-perfect situations they can
become massively infected. For example, have you ever heard of an outdoor
plant having a massive scale infestation? It's rare, because the plant's own
defenses combined with natural preditors keeps the scale population down.
When infestations occur you should always try the safe methods first. Soaps,
oil, alcohol, etc are very effective. Toxics chemicals shoudl always be a last
ditch effort. Has anyone ever tried using other insects to destroy eat the
scale? The MSU Botany Greenhouse manager uses a bug he dubbed 'The Mealybug
Terminator' to eat the scale and mealybugs on the Cycads. Maybe it would work
on CP.
Just a suggestion,
JMS