Abstract:
Effects of widescale locust control with insecticides on non-target edible insects have been scarcely assessed. This study was carried out to investigate the effect of spraying desert locust with cypermethrin and chlorpyrifos on: (1) termite mound activity; (2) safety of edible termites from contamination with pesticide residues; and (3) nutritional composition of non-target edible termites. Incidences of inactive termitaria in the sprayed and unsprayed sites were enumerated. Edible soldiers of Macrotermes spp. from sprayed and unsprayed colonies whose alates swarm around dusk, midnight and dawn were analysed for cypermethrin and chlorpyrifos residues, and proximate, mineral and flavonoid compositions. The pesticide sprays did not influence the incidence of inactive termitaria. No cypermethrin and chlorpyrifos residues were detected in the termites. Chlorpyrifos spraying lowered crude fibre and protein contents in soldiers of dawn and midnight swarming colonies, respectively; whereas cypermethrin spraying lowered ash and crude fat contents in soldiers from dawn and dusk swarming colonies, respectively. Cypermethrin spraying increased moisture content in soldiers from midnight swarming colonies. The level of manganese in soldiers from dawn swarming colonies was lowered by cypermethrin spraying, while contents of aluminium and cobalt from the same type of colony were lowered by chlorpyrifos spraying. However, levels of calcium, potassium, magnesium, phosphorus, zinc, aluminium, manganese and iron were enhanced in soldiers from different termite colonies sprayed with cypermethrin and/or chlorpyrifos. Similarly, soldier termite samples from both insecticide sprayed sites contained higher flavonoid levels than the samples from unsprayed sites. Freedom of the edible soldier termites from the pesticides residues renders them safe for consumption. The results provide insights into the likely effects of wide-scale pesticide sprays against locust on the nutritional profiles of edible termites.