This species was first described in 1982 by B. A. Holloway and the holotype specimen is held in the New Zealand Arthropod Collection at Landcare Research. C. otagensis is a small beetle measuring between 2.4–2.7mm in length and has a width of 1.3–1.4mm. Its head is covered with silver and yellow scales and its body also has mainly yellow and silver scales but with dark brown scales scattered amongst them. One specimen was dissected and evidence of fungi, possibly of the genusStigmella, was found in its gut indicating that C. otagensis feeds upon that genus of fungi.