Population density of Eurygaster integriceps (Het., Scutelleridae) and spatial distribution pattern of its nymphs on irrigated wheat field in Chadegan city

The Sunn-pest, Eurygaster integriceps Put., is the most important insect pest of wheat and barley in Chadegan city, in Isfahan province. This study was conducted on a farm with an area of one hectare in 2015 and 2016 in Chadegan county. In this research with sampling regular population fluctuation and spatial distribution nymphal stage different by using Taylor’s power law and Iwao’s patchiness regression was calculated. Based on the results of Taylor’s power law in 2015 (except 5 nymphal stage) and 2016 the spatial distribution of nymphal instars different, was determined aggregated. In Iwao’s patchiness regression, the spatial distribution of nymphal stages different in 2015, was determined aggregated and in 2016 the spatial distribution except 3 and 4 nymphal instars, was determined aggregated. Upon the results of this research, appearance date 1st to 5th nymphal instars in 2015 were observed in 10th, 16th, 16th, 19th and 26th May respectively. appearance date 1st to 5th nymphal instars in 2016 were observed in 18th, 21th, 23th, 31th May and 4th Jun respectively. Maximum density population 2nd nymphal instar that is the best time for control sunn pest was observed in 2015 and 2016, 30th may (2.43±0.65) and 4th Jun, respectively