Blue grama grass genotype affects palatability and preference by semi-arid steppe grasshoppers.

Abstract The semi-arid shortgrass steppe ecosystem of North America is dominated by blue grama grass (Bouteloua gracilis), a species with substantial intraspecific variability, ecological significance, and economic value. Yet no studies have addressed within species differences in blue grama palatability or insect herbivore preference with respect to plant traits. We performed an experimental study to test the palatability and preference of two blue grama genotypes, wild type versus cultivar, by grasshopper herbivores in the Gomphocerinae subfamily. We found strong evidence that cultivar blue grama was more palatable than wild type and that grasshoppers preferred cultivar plants. Although we could not detect differences in silica content between the two types, we found that cultivar plants were larger, had lower water content, and surprisingly, had reduced nutrient value (greater C:N). These results suggest that intraspecific variation in blue grama size and water content could influence feeding choices by this group of grasshoppers. Conservation managers will have to consider such variation when considering how remnant and restored prairies might be affected by these arthropod herbivores. Highlights • Plant palatability and preference by grasshopper herbivores differs between cultivar and wild type blue grama grass. • Cultivar plants were larger and had lower water content, but silica content did not differ. • Surprisingly, cultivar plants had reduced nutritive value (higher C:N) which indicates other drivers for palatability and preference. [ABSTRACT FROM AUTHOR]