'larvicide-related' is a compound formed from 'larvicide' + 'related'. 'larvicide' originates from Latin elements: 'larva' (Latin 'larva' meaning 'ghost' and later used for insect 'larva') plus the suffix '-cide' from Latin 'caedere' meaning 'to kill'. 'related' comes from Latin 'relatus', the past participle of 'referre' (to bring back, to relate).

'larvicide' was coined in modern scientific/medical English by combining 'larva' and the productive suffix '-cide' (used in words like 'insecticide' and 'pesticide'), and retained the sense 'agent that kills larvae'. 'related' passed into English via Old French/Latin (relatus) and came to mean 'connected' or 'having a relation to'. The compound 'larvicide-related' is a modern English adjectival formation attaching '-related' to a technical noun.

Individually, 'larvicide' originally denotes 'a substance that kills larvae' and has kept that technical meaning; 'related' initially meant 'brought back' in Latin but evolved to mean 'connected' or 'pertaining to'. Together the compound means 'connected with or pertaining to larvicides'.