They are yellowish to orange red in colour with a black stripe on the anterior pronotal edge sometimes broke in the middle.

][dubious – discuss] Coridius ianus has been used in numerous physiological and anatomic studies that have demonstrated their strong cibarial muscles used for sucking sap.

[5][6] Like other bugs they produce defensive chemicals from metathoracic scent glands opening ventrally at the base of the third coxae.

They produce chemicals that include 4,5-dimethyl diazole, (E)-2-hexenyl acetate, O-iso butenyl phenol, undecane, undecylamine, 1,12-Dodecan-diol and N-methyl dodec-6,10 diene amine.

[7] These chemicals are known to repel ants (Anoplolepis longipes) and beetles and the effectiveness of a mixture of the key compounds trans-2-hexenal; n-tridecane (60:40 by weight) was greater than with comparative alkanes of shorter or longer lengths.