Jackfruit Shoot Borer

📖 Description

Diaphania caesalis, the Jackfruit Shoot Borer, is the most important lepidopteran pest of young jackfruit plantations in India. Jackfruit (Artocarpus heterophyllus) is increasingly recognised as a high-value underutilised fruit crop in India — the world’s largest jackfruit producer — and the area under managed jackfruit orchards (as opposed to scattered backyard trees) has expanded rapidly in the past 15 years, particularly in Kerala’s ‘Jackfruit 365’ campaign, in coastal Karnataka, and in the North-Eastern states. This shift from backyard tree to orchard crop has been accompanied by an increase in the economic importance of D. caesalis — in backyard trees the pest is tolerated, but in commercial orchards the stunting of young trees and delayed fruiting translate directly to lost revenue. The female moth lays eggs singly on the tenderest part of the new shoot flush — usually the unfurled central leaf — and the emerging larva bores downward into the shoot tip, killing the apical meristem. The damage forces lateral bud break below the bore-hole, producing multiple competing shoots that weaken the tree’s structure and delay the formation of a strong central leader. The pest is most damaging in young plantations (1–4 years) and on highly fertilised trees that produce continuous tender flushes — older trees with harder shoots are much less affected. IPM packages developed by IIHR Bangalore and CPCRI Kasaragod emphasise weekly shoot pruning, Btk applications, and balanced nutrition as the core management tactics.