I was in my yard wearing a LED white headlamp and noticed that the white weevils were very visible at night. The contrast of their white bodies, the green leaves, and the darkness really made them very visible. So I decided to remove some weevils. The technique that worked best for me was cupping one hand under the weevil on the leaf, then using the other hand to knock the weevil off of the leaf into my other hand. Then immediately smoosh them. I wore leather gloves. My mango trees are relatively small, so this was easy to do.
I noticed several things:
The vast majority of weevils were on mango trees going thru growth flushes (for me those were Coconut Cream, Carrie, and Sunrise). Perhaps trees going thru growth flushes taste better?
A majority of single weevils were on the underside of the leaves.
A majority of single weevils were on or near the tip of the leaves.
A majority of the time only a single weevil occupied a single leaf (like it was their territory).
A majority of single weevils were on the west side of the tree.
A majority of couple weevils (weevils fornicating) were on the northeast side of the tree. This was only on my Sunrise.
A majority of couple weevils were closer to the middle of the leaf.
Based on this small sampling...it appears the weevils have a sort of social culture where the single weevils hang out in a certain part of the tree on the underside of tips of leaves. Couple weevils go to a different part of the tree and occupied a middle part of the leaf. This was a relatively small sampling, so you may not be able to draw any conclusions.
Hope this helps in your weevil erradication or at least gets you thinking of ways to get rid of them.