Tyrosine-mediated cuticle tanning (pigmentation and sclerotization) is a vital process for insect growth and development. In this metabolism, dopamine and N-β-alanyldopamine (NBAD) are major precursors to black melanin-like and yellowish quinonoid pigments, respectively. NBAD synthase (Ebony) catalyzes the synthesis NBAD by conjugation of dopamine and β-alanine, while NBAD hydrolase (Tan) dose a reverse reaction of NBAD synthesis catalyzed by Ebony. In this work, we cloned cDNAs of ebony and tan from two beetle species, Tribolium castaneum and Tenebrio molitor. Loss of function phenotypes produced by RNAi for these genes indicate that Ebony, but not Tan, is required for cuticle pigmentation in both beetles. This work was supported by NRFs (NRF-2015R1A2A2A01006614).