Exploring the spatial and temporal dimension of yellow stem borer in coastal rice ecosystem for enhanced management using geostatistical analysis

Rice (Oryza sativa L.), a staple food crop in tropical and subtropical regions, is highly susceptible to damage from the yellow stem borer (YSB), Scirpophaga incertulas (Walker), causing significant economic losses. This study investigates the spatial and temporal dynamics of YSB populations and associated damage in a micro-scale rice landscape in coastal Andhra Pradesh, Southeast India. A total of 5,408 YSB males were captured using pheromone traps, and significant variations in YSB populations and damage were observed across different years and months (P < 0.05). Peaks in YSB activity occurred during the tillering stage in August and from flowering to the grain-filling stage in November. Surface air temperature, humidity and rainfall showed significant positive correlations with YSB populations and damage, while remotely sensed data, including LST and NDVI, had negative associations. Geostatistical analyses revealed a strong spatial aggregation of YSB populations and damage, particularly in August and November, with spherical variogram models providing the best fit. The average spatial dependency of YSB population and damage in rice was estimated to 584.1 m and 673.33 m, respectively. Additionally, spatial autocorrelation (Moran’s I) confirmed significant clustering of YSB populations, while Getis-Ord Gi* analysis identified hotspots in southeastern locations of study area, indicating areas of higher infestation. These findings suggest that incorporating spatial data into pest management strategies can enhance the precision of insecticide applications, reduce environmental impacts and improve the overall efficiency of YSB control. This study provides valuable insights for developing more effective integrated pest management (IPM) strategies for rice cultivation.