NOVELTY - Process (P1) for isolation and purification of alpha -linolenic acid (ALA) from basil seeds (Ocimum basilicum() involves: (A) extracting oil form 150-200 g basil seeds with 18-25 wt./vol.% n-hexane by 12 circulations; (B) hydrolyzing 50 g basil seed oil with 12% potassium hydroxide base for 6 hours; (C) separating ALA from basil seed oil with using a solution of urea in methanol at ratio of 1-3.5 and crystallizing at -6 to 6 degrees C; and (D) separating ALA by silica gel column and n-hexane-ethyl acetate-ether eluent.    USE - For isolation and purification of alpha -linolenic acid (ALA) from basil seeds (Ocimum basilicum(); for conversion of ALA molecule into sex pheromone precursor molecules; and for converting sex pheromone precursor molecules into insect sex pheromone molecule, such as sex pheromone molecules of Manduca sexta and Glyphodes pyloalis, used for attracting Manduca sexta and Glyphodes pyloalis insects respectively, and for use as bait in tangled trap insects (mass trapping) or mating disruption of insects (all claimed) where insects attack crops of tobacco, tomato, potato, eggplant, cherry, and mulberry plants.    ADVANTAGE - The process involves isolation of ALA from basil seed oil, conversion of ALA molecules into ALA isomers that are used as sex pheromone precursors, followed by their reduction, and oxidation of methyl alcohol isomers of linolenic acid to aldehyde or subjecting them to acetylation, where sex pheromone ALA isomers are useful to attract Manduca sexta and Glyphodes pyloalis insects. The pheromone synthesis process is simpler and more economic. The produced sex pheromone molecules have physico-chemical characteristics similar to natural sex pheromone molecules of insects i.e. insect sex pheromone molecules produced are homologous to those of Manduca sexta and Glyphodes pyloalis. Both molecules have high oxidation stability against oxidation by air and/or UV rays, and are capable of producing insect attractant response through antennae of insects. The sex pheromone molecules homologous to those of Manduca sexta and Glyphodes pyloalis can attract Manduca sexta and Glyphodes pyloalis insects respectively, and are useful as bait in tangled trap insects (mass trapping) or mating disruption of insects for insect control in integrated manner. Thus sex pheromones can be used as bait for controlling insects in environmentally friendly manner and support green chemistry.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) process (P2) for conversion of ALA molecule obtained by the process (P1) into a sex pheromone precursor molecules having unsaturated carbon at the same position and with geometry of the sex pheromone molecules, involving: refluxing ALA in alkaline condition using 21% KOH and ethylene glycol at 180 degrees C for 25 minutes; (2) process (P3) for converting the sex pheromone precursor molecule obtained by the process (P2) into a sex pheromone precursor molecule having -CH2OH functional group, involving: (a) forming methyl ester of ALA conjugated isomers using methanol with concentrated H2SO4 catalyst under reflux at 50 degrees C for 1 hour; (b) separating the methyl ester of ALA conjugated isomers by column chromatography using silica gel impregnated with AgNO3; and (c) changing the functional group of the methyl ester of ALA conjugated isomers with the geometry and position of the C10, C12, or C14 by using NaBH4/tetrahydrofuran (THF) while refluxing at 70 degrees C and etching with methanol; (3) process (P4) for converting the sex pheromone precursor molecule obtained by the process (P3) into insect sex pheromone molecules of Manduca sexta involving: converting the functional group -CH2OH in the molecule to -CHO, by treating with a mixture of pyridinium chlorochromate (PCC) and sodium acetate (NaOAc) at a ratio of 50 and using CH2Cl2 solvent; and (4) process (P5) for converting the sex pheromone precursor molecule obtained by the process (P3) into insect sex pheromone molecules of Glyphodes pyloalis involving: converting the functional group -CH2OH in the molecule to -CH2-OCOCH3 by treating with graphite bisulfate catalyst in cyclohexane solvent.