Spatial genus differences in grasshopper catches had no clear linear trend at six Konza watersheds in 1997–2020

We tested whether grasshopper genus mixes became more similar among six fixed, ungrazed Konza Prairie watersheds in 1997–2020. The panel has 576 surveys, four 200-sweep surveys per watershed-year, and 35,785 insects in 22 named genera. The primary measure was the annual mean squared genus-share distance among 15 fixed watershed pairs. We corrected it for individual count noise under an independent multinomial sampling assumption. Its fitted slope was −0.0056 per decade. The nominal 95% interval from 9,999 four-year residual block draws was −0.0335 to +0.0225. The direction of spatial change was uncertain. All planned corrected-distance checks also had intervals that include zero. Conventional distances and Bray–Curtis at a fixed catch size gave the same uncertainty. The distance parts for Orphulella and Phoetaliotes changed in opposite directions and partly cancelled. These are exact descriptive parts, not separate genus tests. Lower catch did not establish increasing spatial similarity in this panel. The result does not show stable communities or true population composition. Dates moved later, the locations have different fire histories, and sweep catches combine capture success and abundance. The package has unchanged source data, provenance, code, all results, figures, independent calculation checks and offline repeat instructions.

grasshoppers · Konza Prairie · spatial composition · genus diversity · count sampling · biotic homogenization · null result · reproducibility