Overview
Banjo and colleagues collected palm weevil larvae and winged termites across Ijebu division, Ogun State, and measured proximate composition, vitamins and three metals (cadmium, zinc and lead) when freshly caught and again after 3 months of storage. The insects were sun dried before analysis. Table 4 prints one value per insect and time point. The manifest lists 2012; the printed issue is 2013 (Vol. 4, No. 1), received August 2012.
Key numbers
- Palm weevil larva (Rhynchophorus phoenicis): cadmium 11.70 mg/kg initially and 10.95 mg/kg after 3 months; lead 41.60 and 39.55 mg/kg; zinc 5.70 and 5.50 mg/kg (Table 4, p. 22).
- Winged termite (Macrotermes bellicosus): cadmium 13.10 and 12.70 mg/kg; lead 42.18 and 40.15 mg/kg; zinc 2.90 and 2.70 mg/kg (Table 4, p. 22).
Methods (brief)
Heavy metals were determined “according to AOAC (2003)”; the instrument, digestion, detection limits and replicate count are not reported. The basis (dry or fresh weight) of Table 4 is not labelled.
Evidence Fitness
Direct evidence for edible insects, but weak: one value per insect and time point, no quality assurance and no stated analytical technique. Lead near 40 mg/kg and cadmium above 10 mg/kg are far higher than most edible-insect surveys, and the small decrease after storage of dried material is unexplained, so the values should be treated with caution. The authors attribute contamination to airborne refinery or mining emissions and pesticide use, without measuring sources.