Pre yellowing of fruit occurs in field. After full yellowing fruit drop.

Yash Punia it's citrus fruit borer flies

Yash Punia apply some pheromone trap in your orchard and collect all infected fruits and destroy them

Pranshu Raghuwanshi I had applied insecticides. All pest are in control but yellowing of fruit continuously increasing.

Yash Punia apply potash and micronutrients combo as soil drench or soil fertilization