Abstract
The fall webworm, Hyphantria cunea Drury is a polyphagus insect native of North America that became an invasive alien species in Italy, Switzerland, Hungary, Romania, Russian Federation, Japan, Korea, China, and New Zealand during last five decades. In August 2002, specimens of H. cunea were found in Iran for the first at the Caspian forests nearby the city of Lasht-e-Nesha, Guilan province. In this area, invasive populations of H. cunea have become widely established during last few years and the species is now considered one of the most important pests from the western province of Ardebil to the eastern province of Mazandaran. Moreover, new invaded areas are detected annually. The species has a broad host, ranging from various species of forest trees, fruit trees, and ornamentals to annual crops, and weeds. The preferred forest hosts include maple alder, elm, oak, ash, willow, wild plum, and apple trees. In the northern forests of Iran H. cunea has two generations per year. Adults of the first and second generation were found in early May and late June, respectively. Infestations of Iranian forests were recorded on a large number of plant species along forest borders, road sides, forest parks, seed and fruit orchards, annual plants, and home gardens. Furthermore, notably non-host plants were orange trees and most of the coniferous species.
To keep this pest under control, a comprehensive program was recently developed by the Department of Forests and Range Protection, Research Institute of Forests and
Rangelands (RIFR) of Iran. A pheromone-based monitoring system was tested to record the population dynamitic of H. cunea, but the pilot experiments failed to attract any conspecifics since males were not lured by using commercial sex-pheromone traps. Therefore, it is considered that the local populations may belong to a different subspecies or race where a diverse sex pheromone blend has evolved. At present, there is an integrated approach in cooperation between RIFR and Göttingen University, aiming to identify the blend components of the sex pheromone of the H. cunea populations in Iran. This study may further confirm the exact taxonomic status of these populations and will be crucial to set up a new pheromone-based monitoring system in order to detect and control H. cunea in Iran.