Title: Comparison of hibernating larvae population structure and damage of Chilo suppressalis in a successive rice cultivation system in Mazandaran
Autore Mehrdad Amooghli-Tabari
Abstract: In the last decade, the development of rice replanting in Mazandaran province has increased the uncontrolled use of insecticides and increased the number of pests in the paddy fields. In this study, various experiments, including determining the density of hibernating larvae, the density of egg clusters in the nursery, determining the contamination of rice plants with tapeworms in the vegetative and reproductive stages in single and double rice cultivation systems In two traditional and mechanized methods in Amol, Babol and Fereydunkenar cities with 12 treatments and three replications in a randomized complete block design. The area of each treatment in the mainland and the nursery was 2000 and 300 square meters, respectively. A sampling of overwintering larvae after rice harvesting, Egg masses was performed in the nursery, and the contamination percentage of dead hearts and the white head was determined. The results showed that the number of larvae per sample unit in the early stages was higher than the final stages, as the transition population of overwintering larvae in single and double culture systems was downward. The highest number of egg masses was observed in double-sowing nurseries and the lowest number was observed in single-sowing. The highest percentage of dead heart was observed in two cultures and the lowest in one culture. Also, the highest percentage of the white head was calculated twice and the lowest percentage was calculated once. The highest yield was estimated in one crop and the lowest in two crops. Differences were also observed between the studied sites and traditional and mechanized planting methods. The general conclusion of the study showed that successive cultivation was higher than one culture striped stem borer infestation and lower yield.
Keywords: Rice. Striped stem borer, Hibernating, Deadhearts, whiteheads.