Spatial distribution patterns and fixed-precision sequential sampling plans for estimating population overwintered adult sunn pest, Eurygaster integriceps Put. in rainfed wheat fields in Ardabil province

The sunn pest, Eurygaster integriceps Put. is an important pest of wheat in Firozabad region of Ardabil province, Iran. In this study the spatial distribution of overwintered adult was investigated in rainfed wheat fields. Then, fixed precision sequential sampling plan was developed and validated for estimating overwintered adult density. Iwao's patchiness regression gave a better fit to data (R² = 0.96) than Taylor power law ((R² = 0.81). The aggregation index (β=1.12) was significantly greater than one. These results indicate that the distribution of overwintered adult sunn pest fits the aggregation model in rainfed wheat fields. Kuno's model was designed for estimating of population density of overwintered adult. Ten independent data sets were used to evaluate the validation of Kuno's plans using resampling by the RVSP. Average sample numbers (ASN) for precision level 0.1 and 0.25 were 101 and 14 quadrats, respectively. This result showed that, the using of fixed precision sequential sampling plan can be useful in rapid estimation of overwintered adult density of sunn pest for managing decision making by reducing the required sample sizes in rainfed wheat fields.