The diseased trees have not yet been removed from the fence. The bark-eating beetle threatens Sarkhas trees, and according to the director general of the environment in the Tehran municipality, not all infected trees have been marked with natural resources, and the municipality is not allowed to cut down trees without this measure. This pest came to the fore in 2015 and broke out three years later; Dehydration and drought are considered the main causes of the spread of this pest, and city officials say that infected trees will cause disease in the rest of the trees if they are not cut down. The Director General of Environmental Quality in Tehran Municipality said that natural resources should have acted 15 years ago to prevent today's conditions. - Link.