Diagnosis. This species can be distinguished from other members of the Callajoppa genus-group by the characters given above in the generic description of Laderrica.

Female. Structure. As in generic description. Colour. Overall colour brownish yellow. Following areas dark brown: antenna except for medial surface of scape; supra-antennal area; vertex; dorsal 0.3 of gena; dorsal 0.3 of lateral area of pronotum except for dorsal posterior corner; mesoscutum; fore and middle tarsi; dorsal surface of middle tibia; hind leg: posterior condyles of coxa, apical 0.7 of femur, tibia, basal 0.2 and apical 0.2 of basitarsus, and tarsomeres 2–5. Following areas fuscous: basal 0.5 of T3 except for apical lateral corners, T4-7, and S5-6. Wings clear except for light brown of apical 0.2 of fore wing. Length. 15.6 mm; fore wing 13.7 (mm).

Male. Unknown.

Type material. Holotype ♀, BRAZIL: Nova Teutonia, 27°11¢ S, 52°23¢ W; 8.ii.1939, “B.M. 1939–181” (Plaumann) [NHML]. Condition of holotype: intact.

Etymology. Named after Paul Feeny, in recognition of his outstanding contributions to the study of the biology of swallowtail butterflies.