Short Version
Yes, naphthalene balls (mothballs) in the crowns of Royal Palms and Coconut can instantly stop beetles from entering, ovipositing and causing damage. Our trials with three balls in one 450ml water bottle show that there are no attacks for 12–14 weeks once the balls are in place.. However, to be clear, this is not a recommended practice, as naphthalene is not approved for use as a pesticide nor for use near crops. It is also water soluble, so it will (there is no question here) enter the palm's sap and tissue if used in the crown.
🛑⚠️ Warning ⚠️⚠️⚠️⚠️⚠️⚠️
Again, although placing mothballs is a widespread practice - we cannot recommend this.
🛑 https://www.youtube.com/watch?v=2SoyZd7Icjo
🛑 https://www.youtube.com/watch?v=Y_FoZOnQu4Q
