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,Ophiostoma ulmi,which is the causative agent of the disease. The sticky conidia of the fungus adhere to the fertilised female beetles & 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 & browning of foliage followed by wilting,defoliation & finally death | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Hart-Davis, Adrienne |
Bildgröße: | 5395 px × 3822 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |