Gummosis and Crown toppling in coconut are due to

Gummosis and Crown toppling in coconut are due to Red palm weevil.
The palm weevil Rhynchophorus ferrugineus is one of two species of snout beetle known as the red palm weevil, Asian palm weevil or sago palm weevil.
The lesions can become longer and appear more like a crack after the nut grows if it stays attached to the palm. They may have gum oozing out of them (gummosis). This damage often causes the young nuts to die and fall early.
In crown toppling, the crown wilts first, and lower leaves will follow, due to damage to vascular tissue. Major symptoms such as crown loss or leaf wilt are usually only visible long after the palm has become infested.