Dr. Phyto

black poplar

Populus nigra

Diseases & pests on this plant

• goat mothCossus cossus

  Large round entry holes (8-10mm) on trunks with sawdust ejection + dark stain below, strong vinegar-like smell from active tunnels (the diagnostic odour), large pink-red larva (up to 10cm at maturity) inside tunnels, severe attacks weaken structural integrity of mature trees + create entry for secondary pathogens.

• honey fungus (Armillaria root rot)Armillaria mellea

  Plants decline, leaf out poorly, then whole branches or the whole shrub/tree dies — often suddenly in summer; under the bark at the base and on the roots there is a sheet of white fungal growth that smells strongly of mushroom; flat black "bootlace" rhizomorphs run through the soil; honey-coloured toadstools may appear in clusters at the base in autumn.

• Phytophthora root + crown rotPhytophthora cinnamomi

  Sudden wilting + collapse of mature trees during summer heat stress, dark sunken cankers at base of trunk often oozing dark sap, root system rotted away to small white feeder roots only, gradual general decline + sparse foliage 1-3 years before final collapse, characteristic V-shaped soil-line lesion when bark peeled back.

• Asian longhorned beetleAnoplophora glabripennisEU-notifiable quarantine organism

  Adult beetles (2.5-3.5cm, black with white spots + long banded antennae) on trunks in summer, large round exit holes (1cm) higher up trunks (not just base — distinguishes from A. chinensis), sap flow + bark damage where larvae enter, sawdust on bark + ground, infested trees killed within 3-5 years.