Nutrition and Heavy Metal Levels in the Mound Termite,Macrotermes bellicosus(Smeathman) (Isoptera: Termitidae), at three Sites Under Varying Land use in Abeokuta, Southwestern Nigeria

Abstract

The consumption of insects, especially termites, has over the years gained attention. This study aims at evaluating the nutritional and heavy metal levels in workers, soldiers and primary reproductives of Macrotermes bellicosus (Smeathman) collected from farmland, a dump site and an industrial estate in Abeokuta, southwestern Nigeria. Proximate analysis was done using standard methods, vitamins were analysed spectrophotometrically while minerals and heavy metal analyses were done using an atomic absorption spectrophotometer. The soldiers and worker termites recorded higher values of ash, crude fibre, crude protein and carbohydrate contents than reproductive termites (queen and king). The reproductives recorded higher fat content than workers and soldiers. The highest ash (2.27 ± 0.02 %), crude fibre (1.04 ± 0.02 %), crude protein (20.96 ± 0.01 %) and carbohydrate contents (3.65 ±0.01 %) were recorded for workers and soldiers collected from the industrial estate. The reproductives from farmland recorded the highest average vitamin contents, 16.96 ± 0.01 mg/g of vitamin A, 2.74 ± 0.01 mg/g of vitamin B and 7.15 ± 0.02 mg/100 g of vitamin C. The lowest vitamin A and B contents recorded for soldiers from the dump site were 15.12 ± 0.01 mg/g and 2.09 ± 0.01 mg/g, respectively, while soldiers from the industrial estate had the lowest (4.51 ± 0.01 mg/100 g) vitamin C content. Castes from the industrial estate had the highest amount of Cu2 (0.076 ± 0.001 mg/1) while the highest values of Cr2 0.226 ± 0.001 mg/1 and 0.223 ± 0.003 mg/1 were recorded for workers from farmland and the dump site, respectively. Lead Pb2 was only detected in the soldier castes. From the results, it can be concluded that termites are rich in crude protein and have a very low tendency to accumulate heavy metals from the soil.