Semi-artificial diet developed for the successful rearing of red palm weevil: Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) in the laboratory

Abstract

ObjectivesThe red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) is the most destructive insect pest of several palm species, worldwide. The maintaining of RPW laboratory colonies for experimentation has been very challenging. We synthesized a standardized semi-artificial diet which is easy to prepare and economical for the rearing of RPW. MethodsThe effects of semi-artificial diet on biological traits related to RPW development were studied at the Economic Entomology Research Unit (EERU), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia. The diet was synthesized by combining shredded date palm petiole tissues, corn flour, wheat flour, ascorbic acid, sodium benzoic, sorbic acid, agar, and distilled water. Three replicates, each containing fifty newly hatched larvae, were reared on the semi-artificial diet. The developmental time of RPWs fed on the newly synthesized diet was compared to the growth rate of conspecifics fed on date palm and previously published artificial diets. ResultsFully-grown larval weight ranged from 4 to 6 g (5 ± 0.19 g), and larval duration ranged from 46 to 57 days (53 ± 0.3 days). Average adult emergence was 58–98 % (78 ± 0.6), with an average weight of 0.90 g for males and 0.97 g for females. Complete life span was between 48 and 98 days (77 ± 0.9 days). On present semi artificial diet, several larvae had 11 larval instars. The diet has a shelf life of at least seven days and can last up to two weeks if properly kept and saved. ConclusionsIn conclusion, the present study proved that semi artificial diet is quite capable for the successful rearing of RPW. The growth and development of RPW larvae reared in this experiment were comparable to those fed on a natural diet.