Question: query regarding management of mango nut weevil/stone weevil 

Answer: cultural control:  collection and destruction of fallen fruits at weekly interval till harvest.
•  destruction of all left over seeds in the orchard after harvest
•  raking of soil below tree (oct-nov and march) which reduces the pest incidence.
 chemical control:  when fruits are of lime size (2.5-4.0cm) spray acephate 75 sp @ 1.5g/l or lambda cyhalothrin 5 ec @0.3ml/l, repeat the spray two weeks after first spray.  spray fentheion /carbaryl at peak marble sized will give about 90% control