نوع مقاله : علمی - پژوهشی
نویسندگان
1 دانش آموخته کارشناسی ارشد جنگلداری، دانشکده منابع طبیعی، دانشگاه ارومیه
2 استادیار، گروه علوم و مهندسی جنگل، دانشکدۀ منابع طبیعی، دانشگاه ارومیه، ارومیه
3 دانشیار، گروه علوم و مهندسی جنگل، دانشکدۀ منابع طبیعی، دانشگاه ارومیه، ارومیه
4 کارشناس ارشد پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان آذربایجان غربی، ارومیه
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: The Zagros forests, the second-largest natural forest ecosystem in Iran, serve as the most extensive and vital habitat for various oak species in the country. The Green Oak Leaf Roller (Tortrix viridana L.) is a key pest affecting these species in the region. While pheromone traps are widely employed in the integrated pest management (IPM) of T. viridana through various methods, their efficacy can vary depending on regional conditions, host characteristics, and the biological traits of the pest. The present study was conducted in the Mirabad region of Sardasht to investigate the pest's biology, the influence of elevation on pheromone trap efficiency, and the effects of trap placement and installation height on the capture rate of T. viridana.
Material and Methods: The biology of the pest was monitored through weekly sampling of different larval instars and pupae. The influence of the host oak species on pest development was evaluated by measuring the weights of final-instar larvae and pupae in the Perdanan and Mirabad regions (each area comprising 1,500 larvae and 1,500 pupae across two species: Quercus infectoria and Q. brantii). To examine the effect of elevation, three altitudinal gradients (1100–1200, 1200–1300, and 1300–1400 m a.s.l.) were selected on eastern-facing slopes. In each gradient, 10 pheromone traps were installed on the outer canopy of Q. infectoria trees (totaling 30 traps). Furthermore, to assess trap placement, 10 traps were positioned inside the canopy and 10 on the outer canopy. The effect of installation height was also evaluated by placing 10 traps at a height of 1.5 meters and 10 traps at 3 meters above the ground. Data were analyzed using SPSS software, version 21.
Results: T. viridana underwent five larval instars, followed by the prepupal and pupal stages. The first pupae were observed in late May. After emergence and mating, the adults began oviposition, completing one generation per year (univoltine). The pest overwinters in the egg stage, with adults remaining active for approximately 30–40 days. The initial emergence of adults occurred in early June, peaking around June 10th, and all pest activity ceased by mid-July. Females lay eggs in clusters of two to four on young shoots near buds, ensuring larvae can feed on fresh buds immediately upon hatching. The larval scales are gray to brown, camouflaging with the branches, which makes visual detection difficult. The average weight of final-instar larvae showed a significant difference (p < 0.05) between the two oak species, with the highest larval weight recorded on Q. infectoria in the Mirabad region. Additionally, the weights of both larvae and pupae in 2021 (1400 AP) showed an increase compared to 2011 (1390 AP), with pupae on Q. infectoria being significantly heavier than those on Q. brantii. Adult capture rates in pheromone traps varied significantly across different elevations, with the highest capture occurring at 1100–1200 m. Traps positioned inside the canopy captured more insects than those outside the canopy, whereas installation height (upper vs. lower canopy) did not significantly affect capture rates. The average captures for traps in the upper and lower canopy were 43 and 46 adults per trap, respectively.
Conclusion: The results indicate that the Mirabad region in Sardasht is experiencing high infestation levels of the Green Oak Leaf Roller, as confirmed by the substantial number of insects captured in pheromone traps. A comparison between 2011 and 2021 highlights a significant population increase and the expansion of the pest across most areas of West Azerbaijan Province. The optimal placement for pheromone traps was identified at an elevation of 1100–1200 m, specifically within the lower half and interior of the oak canopy. In areas with high pest density, installing traps in the upper canopy is not recommended, as it is less efficient and increases the time and effort required for control operations.
کلیدواژهها [English]
)