Tobacco alkaloid insect repellent in plants

A method for treatment of an agricultural crop or plant, comprising:

• applying a formulation of a compound of Formula (I) to the agricultural crop or plant;
• repelling or reducing infestation of the agricultural crop or plant by a hemipteran insect by application of the formulation;
• wherein the hemiptereran insect is a sap-feeding insect:
• wherein
• R represents hydrogen or C1-C5 alkyl, and
• represents a single or double bond.

A method to repel hemiptereran insects from an agricultural crop or plant, comprising:

• preparing a concentrated formulation of a compound of formula (I);
• diluting the concentrated formulation in water to a predetermined dilution ratio or concentration;
• applying the diluted formulation to leaves of the agricultural crop or plant;
• wherein
• R represents hydrogen or C1-C5 alkyl, and represents a single or double bond.