Evaluating a semi-synthetic diet for rearing the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae)

Experiments were performed to evaluate the effectiveness of a semi-synthetic diet developed from locally available ingredients in Saudi Arabia for the laboratory rearing of the red palm weevil Rhynchophorus ferrugineus Oliv. The diet was developed based on existing literature, in addition to screening for a number of ingredients from locally available materials. Maize flour, wheat flour, shredded date palm frond tissue and distilled water were chosen as the final ingredients for the diet. Red palm weevils were successfully reared on this semi-synthetic diet and these ingredients were found capable of supporting larval development. However, larval weight decreased on this diet. The larval growth rate on the semi-synthetic diet was comparable to the standard growth rate achieved on date palm. One additional larval instar was observed on the diet. No significant differences were observed in the tested behavioural parameters between females fed the semi-synthetic diet versus those fed the natural diet. In conclusion, red palm weevils can be successfully reared on this semi-synthetic diet, and further optimization of it is warranted.