Neoscytalidium novaehollandiae as a Causative Agent of Tree Decline in Urban Forests and Its Potential for Transmission by Reservoirs

Populations of urban forest trees have declined in recent decades owing to various threats. The present study focused on the role of biotic agents, as there is a lack of detailed long-term records on diseases affecting urban forest trees. Pathogenic fungi from Acer negundo, A. velutinum, Ailanthus altissima, Albizia julibrissin, Carpinus betulus, Chamaerops humilis, Cedrus atlantica, Cercis siliquastrum, Cupressus arizonica, Fallopia aubertii, Fraxinus excelsior, Gleditsia triacanthos, Hibiscus syriacus, Haloxylon ammodendron, Juglans regia, Malus domestica, Morus alba, M. nigra, Nerium oleander, Paulownia fortunei, P. tomentosa, Platanus orientalis, Populus nigra, P. alba, Punica granatum, Quercus castaneifolia, Robinia pseudoacacia, Salix alba, S. babylonica, Tilia platyphyllos, Ulmus minor, Vitis vinifera, and Wisteria sinensis were isolated in the present research. The pathogenic fungus Neoscytalidium novaehollandiae was identified based on morphology and molecular investigation of the TEF-1a and LSU regions. Hence, for the first time, we report 30 new hosts of N. novaehollandiae in Iran and 29 new hosts worldwide. Most isolates were pathogenic to 22 plant species, and some isolates were associated with disease for 10 plant species. Additionally, we determined potential vectors and reservoirs for pathogenic fungi in Aeolesthes sarta, Capnodis tenebrionis, Scolytus kirschii, Orthotomicus erosus, and Microcerotermes gabrielis. To the best of our knowledge, the results indicated that these insects and termites have the potential for the transmission and maintenance of N. novaehollandiae.