Feeding preferences of the field cricket Scapsipedus icipe (Orthoptera: Gryllidae) for different species of Commelina

The field cricket, Scapsipedus icipe Hugel and Tanga (Orthoptera: Gryllidae) is edible and could be used to reduce malnutrition in Sub-Saharan Africa. As the demand for cricket products is increasing, there is a need to find cost-effective ways of rearing this cricket using locally available and affordable sources of food. This study evaluated the feeding preferences of the field cricket S. icipe for 11 species of dayflowers (Commelina spp.; Commelinaceae), using no-choice and multiple-choice experiments in controlled environments. Leaf feeding rates and the nutrient content and phytochemicals of the plants were determined. The ANOVA results indicate significantly higher feeding rates when offered Commelina petersii and C. forskaolii, than Commelina sp. and C. purpurea in no-choice experiments. Multiple-choice experiments ranked C. petersii as the most preferred species followed by C. forskaolii and the two reference species, C. benghalensis var. benghalensis (non-hybrid variant) and C. benghalensis (hybrid variant). The Spearman correlation and PCA revealed positive significant associations between leaf feeding and Ca and NDF content of leaves and a negative significant association between Ca and NDF. A high Ca/low NDF content was recorded for C. petersii and a low Ca/high NDF content for C. purpurea. The beta regression analysis and a biplot identified six phytochemical constituents influencing leaf feeding: phenols, alkaloids, tannins, glycosides, saponins and anthraquinones. Phenols stimulate feeding by S. icipe on C. petersii and C. forskaolii, whereas the tannins and alkaloids in Commelina sp. and C. purpurea, acted as deterrents. Nutrient content and phytochemicals are two important factors determining the suitability of species of Commelina for the field cricket S. icipe. Based on the results of this study, the leaves of C. petersii are highly recommended as a source of food for the mass rearing of this field cricket (S. icipe) and boosting entomophagy in Sub-Saharan Africa.