Birdmanmar,
You are on the right track - stressed plants do give off a "signal" that attracts pests. In fact, one way to find out if your plants are in trouble is if they begin to be infested with pests. A few pests are normal (but unacceptable to us gardeners) but excessive numbers are a sign that something is amiss with your plant. I also note that you mentioned switching your soil mix to an acidic blend. That is significant because I have found that many aroids prefer an acidic blend/fertilization, particularly Alocasias and Anthuriums. In fact, I had some Anthuriums that were barely hanging on until I started giving them Miracle Gro acid blend (for azaleas and rhododendrons). Some of the finickiest Alocasias are finicky in part because they don't get the acidic mix and fert they really need. So they rot instead.
IMHO, when a plant begins to succumb to pest infestation, it is nature's method of taking the plant out of an unsuitable niche. If a niche is suitable, the plant thrives and pests cannot overtake it, but if the niche is unsuitable, the plant will be "forced out" of the niche to make way for a more suitable plant. So if we want to keep a plant "in captivity", we have to make the niche as suitable to it as possible, which means paying more attention to things like soil pH as well as soil medium composition, watering, light, temperature, nutrition and aeration. Growing plants in containers and gardens is growing them outside of the natural balance so we must be responsible for providing the proper balance, or nature will do it for us, even if it means we lose the plant!
LariAnn
Aroidia Research
