Sapota seed borer is an invasive pest that might have been accidentally introduced in India from Sri Lanka a decade back.
The seed borer attacks immature fruits and it is difficult to distinguish between infested and uninfested fruits prior to the emergence of larvae.
Tiny holes
Fruits with tiny exit holes are the only indication of seed borer infestation. During the tunnelling process, the larva drags out the excreta from the seed to the pulp.
Majority of the larvae emerge from the seeds after feeding on the cotyledons completely and prior to ripening of the fruit.
Small black ants inhabit such damaged fruits. The larva on exiting from the fruit cuts a leaf and folds it over to make a fine shell-like structure within which it pupates.
The adult is a small delicate greyish white moth with bell shaped wings and resembles bird droppings.
The seed borer incidence depends on the variety and availability of susceptible stage of fruits (marble-lime size fruits).
There is no variety that is completely resistant to the seed borer infestation.
Management
After main fruiting season, the pre-seasonal stray fruits serve as source of survival during off season.
Thus, Sanitation is to be maintained for eliminating the sources of seed borer infestation.
Collection and destruction of the off season stray mature fruits after main harvest till November will bring down the pest incidence.
Erecting light traps in the field during cropping season will attract adult moths and will minimize the incidence.
Effective management of seed borer relies primarily on the stage of spray intervention. The time of application is crucial in the management of seed borer.
Spraying
First spray intervention should be made when the fruits are of small lime size and thereafter the sprayings should be repeated at fortnightly intervals during main fruiting season.
Alternating the sprays of Deltamethrin 2.8 EC at 1 ml/l and Bt at 1 ml/ at fortnightly interval will bring down the seed borer infestation.
Division of Entomology and Nematology, Indian Institute of Horticultural ResearchHesseraghatta Lake POBangalore
