Forecasting the phenological development of harmful non-gregarious locusts in the agroclimatic zones of Kazakhstan based on spatial analysis
DOI:
https://doi.org/10.51452/eaj.2026.3(131).2284Keywords:
harmful non-gregarious locusts; phenological development; phenological forecasting; agroclimatic zones; spatial analysis; phytosanitary monitoring.Abstract
Background and Aim. Forecasting the phenology of damaging non-gregarious locusts allows timely
organization of phytosanitary monitoring, optimizing survey timing. The goal of the research was to identify the spatial features and trends over time in the period of mass emergence of damaging nongregarious locust nymphs across agro-climatic regions of Kazakhstan using data from phytosanitary surveillance conducted between 2003–2025.
Materials and Methods. Long-term data on the dates of phenophases in harmful non-grasshopper species from regions of Kazakhstan are presented. The calendar date of massive nymph emergence was transformed to day-of-year (DOY). Spatial analyses were carried out with consideration of agroclimate zoning according to thermal and water supply criteria. Differences between zones were assessed using the Friedman test, consistency of the spatial order was assessed using Kendall’s coefficient of concordance, long-term trends were assessed using the Mann–Kendall test and Sen’s slope estimator. The spatial stability of the phenological regime was assessed using Spearman’s rank
correlation coefficient.
Results. Spatial variability of time of mass nymphs hatching for agro-climatic regions of Kazakhstan revealed. Difference between minimum and maximum dates – 23 days (April 21 in dry-hot region up to May 14 in very-wet moderately-warm region); differences between regions are significant (χ2=226.0; p<0.001), stability of spatial pattern is high (W=0.983). Statistically significant trend towards earlier
nymph hatching was -0.20 days/year (p=0.010) with preserved spatial pattern (rho = 0.995); model with fixed effects of district and year accounted for 98.9% variance in hatching dates; estimated time from mass hatching until reaching second instar was 13–16 days.
Conclusion. Agroclimatological zonation allows considering the space-time variability of phenology of damaging nongregarious locusts. The obtained results may find application in differential scheduling of phytosurveys and optimization
