The present invention relates to agrochemical and biological control compositions for combating pests, more specifically plant pests, comprising at least one polypeptide, which specifically binds to a pest. The invention further provides methods for protecting or treating a plant or a part of a plant from an infection or other biological interaction with a plant pathogen, at least comprising the step of applying directly or indirectly to a plant or to a part of a plant, an agrochemical composition, under conditions effective to protect or treat a plant or a part of a plant against a infection or biological interaction with a plant pathogen. Further provided are methods for producing such agrochemical compositions and formulations, to polypeptides with a specific pesticidal activity comprised within an agrochemical formulation, to nucleic acids encoding such polypeptide and to plants comprising chimeric genes comprising such nucleic acids.