The World species of Rhopalocerus Redtenbacher are reviewed, figured and keyed. The following new species are described: B. camerunensis (Cameroon); B. viti (Togo); B. mirei (Cameroon); B. minimus (Madagascar); B. tuberculatus (Madagascar); B. compa- ctus (Key Island); B. papuanus (New Guinea); B. iviei (New Guinea); B. solomonensis (Solomon Isl.). The generic names Corticoides Fairmaire and Bhopalocerophanus Helleb are considered as synonyms of Bhopalocerus, which forms monogeneric tribe Bhopalocerini. The immature stages and biology of B. rondanii (Villa et Villa) are fully described for the first time. A preliminary key to the World tribes of Oolydiidae and brief discussion are provided.