'larvae-free' originates from English, specifically the words 'larvae' and 'free', where 'larvae' comes from Latin 'larva' meaning 'mask' or 'ghost' and 'free' comes from Old English 'frēo' meaning 'not captive; free'.

'larvae' entered English from New Latin (from Latin 'larva') in scientific usage to mean the immature form of an insect; 'free' evolved from Old English 'frēo' through Middle English to modern 'free'. The compound 'larvae-free' is a modern English formation combining the plural noun and adjective to denote absence of larvae.

Initially, Latin 'larva' meant 'ghost' or 'mask'; over time it acquired the biological sense 'immature insect stage' and, combined with 'free', produced the modern meaning 'without larvae'.