I. Merlin Kamala^1,, C. Chinniah¹, J.S. Kennedy², M. Kalyanasundaram², M. Suganthy¹

Saturated hydrocarbons of fresh healthy jasmine buds (Jasminum sambac L) and infested buds damaged by blossom midge, Contarinia maculipennis Felt. were identified through Gas Chromatography-Mass spectrometry (GC-MS) to determine the saturated hydrocarbons. The results revealed that both the healthy and damaged buds had emitted hydrocarbon compounds numbering 24 and 34 respectively. The variation in the hydrocarbon constituents of healthy and damaged buds clearly depicts the emission of volatiles attracting beneficials witnessing tritrophic interactions in jasmine ecosystem. Linalool, the fragrant compound is detected in healthy jasmine buds at the retention time of 9.278 mins with the largest peak area of 5180722 mm² and in midge damaged buds in a peak area of 288967 mm², which might be the probable reason for the fragrance of jasmine flower. Allyl isothiocyanate, a compound responsible for plant defenses against herbivores is detected at a retention time of 4.306 mins recording the sixth largest peak area of 2461362 mm² in midge infested buds. Other plant defense chemicals viz. naphthalene, azulene, methyl salicylate, methyl anthranilate, alpha farnescene, phenol, styrene etc. were also detected in midge damaged buds. The quality and quanity of these semiochemicals emitted by the buds might be the reason for attraction of natural enemies in the jasmine ecosystem there by further reducing the infestation of midge, as well as other pests. This feature can be exploited to enhance the efficacy of natural enemies in integrated management of jasmine pests.

semiochemicals, synamones, saturated hydrocarbons, Hendecasis duplifascialis, GC-MS, jasmine