Mid 19th century; earliest use found in Robert Mayne (1808–1868). From classical Latin merdamerd + -ivorous. R. G. Mayne gives a Latin form merdivorus.
Definition of merdivorous in US English:
merdivorous
adjectiveməˈdɪv(ə)rəs
rare
Of an insect: that feeds on dung; coprophagous.
Origin
Mid 19th century; earliest use found in Robert Mayne (1808–1868). From classical Latin merda merd + -ivorous. R. G. Mayne gives a Latin form merdivorus.