Heterodiomus brethesi is a species of beetle of the family Coccinellidae. It is found in Chile.

Description Adults reach a length of about 1.4–1.5 mm. Adults are pale reddish yellow, with the scutellar area of the elytron obscurely darkened.

Etymology The species is named for Jean Brèthes, the author of Heterodiomus and a significant figure in the classification of South American Coccinellidae.Descriptions of the male of Heterodiomus marchali Brèthes and a new species of Chilean Heterodiomus Brèthes (Coleoptera: Coccinellidae: Scymninae: Diomini)

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