For the first time data on behavior, hostplants and immature stages for a member of this rare Saturniidae are presented. A female of Almeidaia aidae Mielke & Casagrande, 1981, the fifth known specimen of this species, was collected in Diamantino, upper Arinos river, Mato Grosso, Brazil, and from its ovae, larvae were reared on Pseudobombax longiflorum (Mart. & Zucc.) A. Rob. and Eriotheca gracilipes (K. Schum.) A. Rob. (Bombacaceae), two tree species common in the cerrado region of central Brazil. Larval development in 10 days is extraordinarily fast, however the pupal period can last a year or more. The types from Almeidaia romualdoi Travassos, 1937 and A. aidae are illustrated in color for the first time; of this last species, eggs, larval instars and adults are illustrated in color and the first and second larval instars and pupa, by line drawings.
Bombacaceae; Brazil; Cerrado; Hostplant; Biology
