Showing 4 results for Grape Leafhopper
M . Latifian, H. Seyedoleslami, J. Khajehali,
Volume 8, Issue 3 (10-2004)
Abstract
Populations of Arboridia kermanshah Dlabola is increasing in Isfahan vineyards. In this study, some morphological characteristics of the immature stages, over wintering sites, number of generations per year, and seasonal population fluctuations of this pest were studied in vineyards in Isfahan Province. Eggs showed apparently four distinct embryonic developmental stages. At 25.8 ±2˚C, development of eggs was completed in 10.9 ± 0.7 days. There were five nymphal developmental stages. Nymphal stages can be distinguished with wing pad development and width of head capsule and width of pronotum. The grape leafhopper overwintered as adults under leaves and crop residues. Rearing studies showed that the grape leafhopper had three generations per year, each lasting 33.9±0.6 (without overwintering period), 46.3±0.7 and 37.3±0.6 days, respectively. Seasonal monitoring of adults, nymphs and eggs showed three or four overlapping periods of activity in the field. Four periods of activities of adults were recorded through season from early May – mid June, mid June – mid July, mid July - late August and early September – mid October.
M. Latifian, H. Seyedoleslami, J. Khajehali,
Volume 9, Issue 2 (7-2005)
Abstract
Some bioecological aspects of grape leafhopper, Arboridia kermanshah Dlabola, including: the egg distribution under the leaf surface, eggs and nymphs spatial distribution on the vine arms, the adult distribution on three strata of the vine canopy, the adult diel activities and the geographical distribution of this species in Isfahan province were studied. Samplings were done in the 1997. The egg distribution under the leaf surface was determined by repeated sampling during the season and the egg density was estimated on three regions such as the main and secondary vein, the leaf surface margins and others. Eggs and nymphs spatial distribution along the vine arms were studied weekly for six weeks by sampling an arm of five vines during the second generation, the leafhopper population was the highest. The adult spatial distribution on the vine canopy was determined by sampling three strata of the vine canopy using the D-vac apparatus. Diel activities were studied by sweeping nets fifty times per vineyard at the two hour intervals from 8 a.m. to 20 p.m. Temperature and the relative humidity were also measured in the shade once per hour. The presence and the abundance of this species in 87 vineyards in the different climatic conditions were studied by a sweeping net. The leaf margin and around of the secondary vein were preferred for the oviposition of the leafhopper. Adults, nymphs and eggs were more abundant in the middle strata of the vine canopy than others. The mean pattern of the daily activity of the adult indicated one peak at 8 a.m. and the other one at 20 p.m. Maximum temperature thereshold for the adult activities was 28º C. The study of the grape leafhopper distribution in isfahan province indicated that this species was distributed in the most vineyards, but was highly abundant in more humid conditions.
M. Latifian, H. Seyedoleslami, J. Khajehali,
Volume 9, Issue 3 (10-2005)
Abstract
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.
J. Khajehali, M. Kohansal, B. Hatami, M. Mobli,
Volume 22, Issue 2 (9-2018)
Abstract
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.
