Disclosed is a solid arthropodicide composition comprising by weight (a) from 0.3 to 100% of a particulate component comprising particles of a solid carrier infiltrated with a mixture comprising (i) one or more carboxamide arthropodicides and (ii) a surfactant constituent; (b) from 0 to 50% of a surfactant component having dispersing and wetting properties; and (c) from 0 to 99.7% of one or more additional formulating ingredients. Also disclosed is a propagule contacted with a biologically effective amount of said composition.