Effect of Dermestes maculatus on the nutritional qualities of two edible insects (Oryctes boas and Rhynchophorus phoenicis)

Abstract

This study aimed to assess the effect on nutritional composition of two ‘Edible Insects’ (Larva of Oryctes boas and Rhynchophorus phoenicis) after infestation by Dermestes maculatus. The study was done over a period of six weeks by subjecting these edible insects to different conditions of storage (using pepper and salt). The assessment was based on weight and proximate analysis differences before and after infestation under these media of storage. The larva of Oryctes boas in the container with salt as preservative had the least weight loss (from 30.00 + .0000 → 39.70 + .3000 → 36.30 + 1.000), followed by the container with pepper as preservative (from 30.00 + .0000 → 31.05 + 5.000 → 25.25 + .1500) while the highest weight loss occurred in the container without preservative constituents (from 30.00 + .0000 → 30.30 + 1.000 → 21.15 + 5.000). Likewise, the larva of Rhynchoporus phoenicis in the container with salt as preservative constituent had the least weight difference of (16.00 + .0000 → 20.80 + .0000 → 13.65 + .1500); followed by the container with pepper as preservative (from 16.00 + .0000 → 16.40 + 1.000 → 6.700 + .2000), while the highest weight loss occurred in the container without preservative (from 16.00 + .0000 → 7.850 + 5.000 → 6.300 + .0000). The mortality rate of Dermestes maculatus was also determined, showing that the larva of Oryctes boas and Rhynchophorus phoenicis containing salt as preservative had the highest mortality rate of 60% and 80%, respectively, followed by that containing pepper as preservative having 20% and 30% respectively, and that containing no preservative constituent had no mortality rate. It was concluded that, Dermestes maculatus’ infestations on the larva of edible insects showed a difference in the proximate analysis of these edible insects before and after infestation. Therefore, it was suggested that edible insects should be well dried and locally preserved with salt and pepper.