Bosara modesta is a moth in the family Geometridae first described by William Warren in 1893. It is found in the north-eastern Himalayas and on Java. The wingspan is about 26 mm. Adults are fuscous, suffused with rufous on the body and base of the wings, which have traces of numerous waved lines. The forewings have an olive-green postmedial line, as well as a fine olive waved submarginal line. The hindwings have double postmedial and single submarginal curved and waved olive lines.