Evaluating the Potential of Edible Insects (Palm Weevil- Rhynchophorus Phoenicis Larvae) as an Alternative Protein Source for Humans

Abstract

Using 24 adults of Rhynchophorus Phoenicis (12 males and 12 females), a four-week experiment was conducted to determine an alternative substrate in raising the larvae as a protein source for humans and the microbial content associated with the production of the larvae. Three treatments were used; Oil Palm Yolk (OPY), Raffia Palm Yolk (RPY) and Sugarcane Substrate (SCS). The palm substrates were harvested and soaked for 3 days for preservative purposes. Five (5) kg each of OPY, RPY and sugar cane (SC) were replicated four times in plastic baskets using a Completely Randomized Design (CRD). The proximate composition of the OPY and RPY substrates were as follows: values for moisture content showed 60.4% for OPY and 61.7% for RPY, crude protein content of RPY (3.5%) and OPY (3.2%), crude fibre content of OPY was 31.1% compared with RPY (29.4%) and ether extract content of 1.2% and 1.6% were recorded for RPY and OPY respectively. The Ash, NDF and ADF values for OPY were 1.6%, 2.4% and 77.5% and that of RPY were 76.4%, 50.2% and 50.1% respectively. Adults placed on all treatments of SCS could not survive making that treatment unsuccessful. All parameters measured for RPS were significantly (P<0.05) higher compared with the OPS except for mortality rate which was statistically (P>0.05) similar. Higher microbial range of 3.4x10⁷ was recorded for OPY which was higher than the acceptable range of 5x10⁶ by the Food Administration Manual. Microbial content detected at the end of the experiment on isolated larvae from RPY and OPY treatments were 9.1x10⁵ and 4.9x10⁵ respectively, which was below the standard range making it acceptable for consumption. It was concluded that RPS was a better substrate for Rhynchophorus phoenicis larvae production since it produced a higher larvae number and also larvae with higher weights.