'aphicidal' originates from modern English formation combining the noun 'aphid' and the adjectival suffix '-cidal' (from Latin roots meaning 'to kill').

'aphid' entered English from New Latin 'Aphis', borrowed from Greek 'aphis' meaning 'plant louse'; the suffix '-cidal' was modeled on Latin-derived formations (compare 'pesticidal', 'insecticidal'), producing the modern coinage 'aphicidal'.

Initially coined to mean 'having the property of killing aphids' and it has retained this specific technical meaning in agricultural and entomological contexts.