Survey on the incidence of jasmine budworm, Hendecasis duplifascialis Hampson and its natural enemies in Tamil Nadu.
Jasmine budworm (Hendecasis duplifascialis), a serious pest of jasmine, poses a severe threat to flower yield. Roving surveys were conducted in 2014-15 in the major jasmine growing districts of Tamil Nadu, to study the incidence of jasmine budworm and the natural enemies associated with it in managing the pest naturally. Field surveys indicated the presence of the pest in the entire surveyed region in varying intensity with maximum incidence recorded in Madurai (35.18%) and Tirunelveli districts (31.35%), respectively. Coccinellid predators such as Cheilomenes sexmaculata, Coccinella transversalis, Scymnus sp., Coccinella septempunctata, Brumus suturalis and Chilocorus sp. were present in the jasmine ecosystem with a mean population of 3.04 coccinellids/plant. Neuropteran predators, Chrysoperla zastrowi sillemi and Mallada boninensis were found effectively managing the egg and early instars of budworm with a mean popularity of 2.2/plant. A wide range of preying mantis and spiders with a mean population of 3.8 and 4.3%, respectively, were present. Larval parasitoids such as Bracon sp. and Phanerotoma hendecasiella played a vital role in natural suppression of the pest. Native weeds and flowering plants such as Parthenium hysterophorus, Rosa sp., Nerium oleander, Vernonia cinerea, Dutura metel, Lantana camara, Tagetes erecta, Ipomea carnea, Helianthus annuus, and Coriandrum sativum provided nectar to the adult stages of the parasitoid. The mean parasitism of the budworm larva by these parasitoids was 2.98%. Thus, jasmine budworm was found to be associated with a rich pool of natural enemies that provided natural suppression, conserved by the flowering plants in the vicinity.