Design and selection of an artificial diet for the coconut black-headed caterpillar,Opisina arenosella,based on orthogonal array analysis

Opisina arenosella has been an outbreak pest of coconut trees in southern China since 2013. To develop efficient control methods for this invasive pest, adequate rearing protocols are desirable. In this study, an orthogonal array of artificial diets with 11 factors at 3 levels was deployed for both 2nd–4th and 5th–6th instar larvae of O. arenosella. Biological parameters including survival time of larvae, development time from larva to pupa, pupation rate, emergence rate, and pupal weight were monitored to reveal the most important components in the diet formulas. Biological parameters in O. arenosella were most affected by brewer’s yeast, sucrose, ascorbic acid, and wheat germ. Statistical analysis indicated that different diet combinations supported optimum performance of biological parameters for 2nd–4th and 5th–6th instar larvae. The validity of the optimization predicted by the orthogonal array analysis was confirmed in a follow-up bioassay with similar optimized diets for both 2nd–4th and 5th–6th instar larvae. The optimal artificial diet has great potential for the mass rearing technique, and can provide valuable results for using parasitoids in biological control of O. arenosella.