I was told this years ago by an inspector from the USDA when I had my nursery, its what
@Daisyl said....and its NOT JUST MEALYBUGS but all sap suckers like scale, spider mites, etc....
If you don't knock down the infestation of adults immediately, and then knock down the new emergent next generation immediately, and subsequent hatchings, the survivors will begin to exhibit resistance to whatever pesticide you are using, and you can end up with insects that will not respond to your attempts at eradication.
Th best way to do this is with a systemic. I know there are not a ton out there that are home gardener user friendly, and some of the best were taken off the market for home garden use years ago because they were just too toxic for the average home gardener to be messing with. But there are still some very effective ones, and if you are diligent and do not miss a sequential treatment, you can get rid of some of them...it may have to become a routine part of your plant maintenance, like watering and fertilizing....every Monday, routine pest control.
I grow almost 100% tropical plants, and I have learned over almost 40 years now which ones are more prone to getting infested, with what insect, and what time of the year it happens.
It has nothing to do with the health of my plants, all are kept in tip top shape as far as nutrition, watering, light, humidity and air movement. I pay a lot of attention to those things.
This is the season that ALocasia, colocasia, heliconia and calathea start to get things like mealies and thrips. I am on the lookout, I am doing pre-emptive strikes weekly.
Fall is the season that the Ti Leaves get mealies. I start treating them in late summer to ward off this.
Anthuriums tend to get scale in the late summer/early fall. So I treat starting mid-summer and continue on a weekly basis until spring.
@Daisyl I do the same thing with my hose end sprayer....set to to 'flat' and basically pressure wash the bugs off the plant!