Hi Chandra,

Against stem girdlers you should first remove and destroy affected branches as a cure.

Several species of beetles from the family Scolytidae attack mango trees. These

insects dig tunnels into trunk or branches, leading in the worst case to plant death. The beetles may  attack trees which have been injuried by wind, hail (and so on), cut back for grafting, or large trees which have been recently transplanted. Vigourously growing mango trees better cope with beetle attacks.

I hope this helps.

Regards,