'non-aphicidal' originates from English, specifically formed from the prefix 'non-' and the adjective 'aphicidal', where 'non-' meant 'not' and 'aphicidal' is built from 'aphid' + the suffix '-cidal' meaning 'killing'.

'aphid' traces to New Latin and ultimately Greek 'aphis' meaning 'plant louse'; the suffix '-cidal' derives from Latin 'caedere' (via '-cida'/'-cid-') meaning 'to kill'. These elements combined into 'aphicidal' (meaning 'killing aphids'), and the modern formation 'non-aphicidal' was created by prefixing 'non-' to mean 'not killing aphids'.

Initially the parts meant 'not' + 'killing (aphids)', and the compound has retained the literal sense of 'not killing aphids' in modern usage.