Effects of Irrigation Regimes on Seasonal Population Dynamics and Damage of Arboridia kermanshah Dlabola on Different Grape Cultivars in Isfahan

The grape leafhopper, Arboridia kermanshah Dlabola (Hemiptera, Cicadellidae), is an economically important pest of most vineyards in Isfahan. The effects of two irrigation regimes [normal (100 liter/ tree/ week) and minimum (100 liter/ tree/two weeks)] seasonal population changes and the damage of A. Kermanshah as well as the percentage of leafhopper egg parasitism by Anagrus atomus were studied on five grape cultivars including Shahani, White Rishbaba, Askari, Black Rishbaba and White Yaghoti; this was done in a completely randomized blockdesign with split plots in three replications at Isfahan University of Technology in the 2005-2006 period. Adults and nymphs were assessed by weekly sampling using a vacuum insect collector (D-VAC). Non-parasitized and parasitized eggs were counted weekly by clipping three leaves from different strata of vine canopy as a sample unit, in each plot. The results showed that the leafhopper population density, damage percentage and egg parasitism in both years of study in the normal irrigation plots were higher than those with the minimum irrigation. The maximum density of adults and nymphs was observed in June and early July on the White Yaghoti. The highest egg density and parasitism were recorded in June and October-November, respectively, on black Rish-baba in the normal irrigation. The highest damage was on the white Yaghoti in August and September, and the lowest damage was on Askari and Shahani, both in the normal irrigation regime.