Moringa / Drumstick borer

Hi
Need help in controlling this borer which goes deep in the main stems of drumstick plants. It grows to about 3" long and small finger size thick and develops wings and moves.
We tried monocrotophos and emamectin benzoate ( Benzer) with little success.
Would appreciate any advise on how to eliminate them
Right now we are chopping off all the infected plants but not sure it will mean controlling this pest from next round of attack.

Thanks