ADAM HART-DAVIS / SCIENCE PHOTO LIBRARY ADAM HART-DAVIS / SCIENCE PHOTO LIBRARY
Dutch Elm disease. The tracks of elm bark beetles on the trunk of an elm tree killed by Dutch Elm disease. The bark-boring beetle is a vector of the fungus Ceratocystis ulmi, which is the causative agent of the disease. The sticky conidia of the fungus adhere to the fertilised female beetles and are deposited under the bark, where they germinate. Infection spreads rapidly, but is confined to the water conducting vessels of the tree. The symptoms of the disease are yellowing and browning of leaf foliage followed by wilting, defoliation and finally tree death.
Model release not required. Property release not required.