Analysis of the Spatial Distribution of Cydia pomonella (L.) in Southern Uruguay Using Geostatistical Tools

Abstract

Geostatistics can support pest management by analyzing the spatial distribution of a pest at a local or regional level. Therefore, specific site pest control can be performed based on accurate spatio-temporal information. Cydia pomonella (L.) (Lepidoptera: Tortricidae), the most serious apple and pear pest, requires several insecticide applications to reduce injury to acceptable levels. The aim of this research was to study the temporal and spatial variation in distribution and abundance of C. pomonella in the main fruit-growing area of Uruguay. From 2007 to 2009, approximately 120 pheromone traps per year were installed in apple and pear orchards distributed over 50,000 ha, and georeferenced. Male adult captures were registered weekly from October to March. Spatial analysis of the captures was done, obtaining semivariograms for the accumulated captures analyzed by generation and by growing season. Maps were constructed based on significant models obtained, where the population level of the pest was estimated using ordinary kriging. The correlation range estimated was from 1720 to 2690 m. Hot spots of high population level and some areas with comparatively low populations were constant over the 2-year period.