Off-season survival of the sapodilla seed borer, Trymalitis margarias in India- a clue for an effective cultural management strategy

Abstract

Sapodilla seed borer, Trymalitis margarias, is causing huge losses to farmers in India. The concealed nature of larvae within the seeds renders the management of this pest a challenge. The sparse and continuous fl owering habit of sapodilla (Manilkara achras) plants after main cropping period makes the survival of this monophagous pest easier during off-season. A continuous monitoring during off-season showed that the stray sapodilla fruits were serving as a potential source of infestation for tortricid seed borer, T. margarias. Correlation analysis between the off-season and main cropping season T. margarias incidence exhibited a signifi cant (P < 0.01) positive correlation (r = 0.85**) with the mean infestation of 19.40% and 23.16%, respectively. Further, a pooled (data over fi ve years) linear regression model showed that variability in the seed borer infestation during main-season can be explained to the tune of 71% through stray fruits alone. Multiple infestations (1-4 exit holes/fruit) were found to be common during off season compared to regular season (1-2 exit holes/fruit). Removal of stray fruits during off-season reduced the seed borer incidence in the subsequent main crop.