Effect of food plant sterilization on growth and nutritional value of adult variegated grasshopper Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae)

K. O. Ademolu, A. B. Idowu, O. A. Olabode, O. Olalonye, A. B. Adelabu and O. Atayese

Abstract
The variegated grasshopper Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae), like other insects, harbors microorganisms in its alimentary canal and these microorganisms gotten from their food plants, play a symbiotic role in the insect host. In this study, the effect of food plant sterilization on the growth and nutritional value of Z. variegatus was investigated. The insects were grouped into two groups of twenty insects each (A and B). Group A was fed with sterilized cassava (Manihot esculenta Crantz) leaves while group B was fed with unsterilized cassava leaves. The body weight and the feed intake of the insects were measured every week using sensitive weighing scale. The nutritional value of the insects in the two groups was evaluated by proximate analysis. It was observed that grasshoppers fed with unsterilized food plant had a significantly higher weight gain (0.42 g) than those fed with sterilized food plant (0.20 g), although the feed intake was not significantly (p < 0.05) different. The fat content, ash content, crude fibre, crude protein and carbohydrate content were also significantly higher (p < 0.05) in the grasshoppers fed with unsterilized food plant (5.82%, 1.67%, 12.29%, 15.85%, and 8.81%, respectively) than grasshoppers fed with sterilized food plant.

Keywords
Food plant, Nutritive value, Sterilization, Zonocerus variegatus.

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References
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