PURPOSE: To obtain the liquid capable of being sprayed on fruits, vegetables, etc., to prevent the adhesion of injurious insects thereto, and non-injurious for men and livestock by compounding vinegar as a main material with other substances such as a garlic extract.

CONSTITUTION: This liquid is prepared by compatibly compounding vinegar as a main ingredient with proper amounts of a garlic extract, Guinea pepper, a salad oil, citric acid, chitosan, an emulsifier, etc., and subsequently diluting the mixture. Especially, a mixture comprising the vinegar, the salad oil and the emulsifier is preferably diluted into a volume of 50-150 times in dependence on a target plant and subsequently sprayed. A liquid comprising the vinegar and the chitosan is preferably diluted into a volume of 50-150 times in dependence of a target plant and subsequently sprayed. The vinegar has an action for stimulating the physiological metabolism of a crop and enhancing the quality of the crop. When the liquid is sprayed on a plant, the natural enemies of injurious insects, such as dragonflies, spiders and ladybirds, quickly escape and do not approach the target plant, until the smell of the liquid is eliminated.