How can I combat mealybug in a large garden?

Question

In my friend's large garden, mealybug is the main pest. They spread quickly, often killing whole plants if left unattended. Sometimes they even attack trees.

The garden and many of its affected plants are rather large, so the process can't require tedious, leaf by leaf removal or application, or anything like that.

My friend has several edible plants and is conscious of the local environment. Therefore, we prefer answers that are as eco-friendly as possible.

The climate is arid tropical, except for periods of heavy rains once or twice a year. We are in southern India.

Answer 1

There are a few options I think will come to good use for you:

1. Use predatory bugs such as ladybugs, lacewing, or the mealybug destroyer Cryptolaemus montrouzieri. These guys should help cut them down.
2. Use a bug blaster attachment to a hose and spray them off to reduce the number of bugs. Use leaf shine or neem oil because this discourages future infestations and the current one.

3. Try insecticidal soap, though I'm not sure if this is safe, but I think it would be. It kills the bugs, so you can spray this on the plants as well. This stuff will dehydrate the bugs and they die within a few hours.

4. If it becomes a huge problem then get a short lived, natural pesticide to treat them. This will not persist in the environment but do check the label.