M. Latifian, H. Seyedoleslami, J. Khajehali. A Model for Tolerance Threshold of the Grape Leafhopper
Arboridia kermanshah Dlabola (Hom.: Cicadellidae). jwss 2005; 9 (3) :231-241
URL:
http://jstnar.iut.ac.ir/article-1-378-en.html
Abstract: (17212 Views)
In 1997, in two vineyards of Isfahan university of technology and Zobeahan in Isfahan, the density fluctuations of Arboridia kermanshah Dlabola and their injury symptoms were studied. In each vineyard three leaves of each of ten randomly selected vines were sampled weekly. Nymphs in different instars were counted directly and rate of injury symptom (leaf discoloration) was determined with planimeter. Special cages were used to determine rate of injury symptom for each nymphal instar in comparison to each other. Rate of injury symptoms and nymphal density indicated two peaks through growing season until harvest. Tolerance threshold for A. kermanshah nymphs was determined 80 first instar nymphal days or presence of 11-12 first instar nymphs and feeding for seven days. With increase of nymph densities, damage symptom increased rapidly.
Type of Study:
Research |
Subject:
Ggeneral Received: 2008/01/9 | Published: 2005/10/15