Syllable division and stress derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
insecticidally is an adverb meaning "by means of an insecticide". It carries one recorded sense.
by means of an insecticide
Definitions, synonyms and semantic relations for insecticidally come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.