Mortality and adult deformation caused by vegetable oils sprayed on Dione juno juno (Cramer, 1779) larvae

Abstract

The management of Dione juno juno (Cramer, 1779) (Lepidoptera: Nymphalidae) larvae in passion fruit has been done almost exclusively with synthetic insecticides. The development of alternative methods is desirable to reduce problems caused by the exclusive use of chemical control. Vegetable oil from cotton seeds (Gossypium hirsutum L.), castor bean (Ricinus communis L) oil, and neem (Azaditachta indica A. Juss) were tested against larvae of D. juno juno, to evaluate mortality of larvae and deformities in adult insects. Treatments included spray solutions with 2.0% of oils (emulsifi ed with detergent). Detergent (1.0%) and distilled water were used as controls. Experiments were conducted for second, third and fi fth instar larvae. Evaluations were performed one and fi ve days after treatment. In the three instars tested, neem oil showed higher percentage of mortality (83. 73 and 64% respectively) than other treatments. Castor bean and cotton oils are more effi cient on second and third larval instar. Spraying of either oil determined deformation in adults. These deformations were more drastic in the insects which larvae were treated with cotton seed oil than neem and castor bean oil.