blacks out the leaves with honeydew

Size
Growth: black, powdery or crust-like coating
Lifespan
1 years
Diet
Saprotrophic: grows on honeydew produced by scale insects and aphids.
Habitat
On leaves bark and branches of trees and shrubs. Grows on honeydew from scale insects.
Range
Throughout New Zealand in forests and gardens. Common in both North and South Islands.
Endemism
Native
Main Threats
No significant conservation threats. Common and widespread. Not affected by habitat loss.
Population
Populations are considered stable and widespread. Common on trees throughout New Zealand.
Conservation Status
Not Threatened
Human Risk
caution
Handling Note
inedible; do not ingest
Conservation Note
Native fungus; not assessed by NZTCS as fungi are generally outside the scope of current threat classifications.
Te Ao Māori
Sooty moulds are named for their black, soot-like appearance. They are common on beech trees in New Zealand forests. The visual impact is significant. The black coating covers the leaves. It does not harm the tree directly. But it can block sunlight if growth is heavy. The honeydew they grow on is an important food source. Native birds like the kākā and tūī rely on it. The cultural layer is minimal. The focus is on ecological function. The fungus is seen as a symptom of insect activity. It is not valued for itself. It is noted for its association with honeydew. The name persists as a descriptor. The observation is practical. The significance is ecological. The fungus remains a marker of forest health. Its presence indicates active insect populations. The connection to native birds is indirect but real. The mould serves as a visual indicator. It highlights the flow of energy. From tree to insect to bird to fungus. The cycle is complete.
It looks like someone has dusted the plant with charcoal powder. Sooty moulds are black, powdery or crust-like fungi. They grow on the leaves and bark of trees. The black coating can cover entire leaves. It blocks sunlight. It reduces photosynthesis. The visual impact is stark. The tree appears diseased. But the fungus is not feeding on the leaf. It is feeding on honeydew. This is a sugary liquid excreted by scale insects and aphids. The insects pierce the plant's sap-carrying vessels. They drink the sugary sap. They excrete the excess as honeydew. The sooty mould grows on this residue. It uses it as a food source. The relationship is indirect. The fungus benefits from the insect's waste. On beech trees, sooty moulds are common. The honeydew is produced by a native scale insect. This same honeydew is an important food source for native birds. The kākā and tūī rely on it. In recent decades, introduced wasps have also discovered the honeydew. They compete with the birds. The ecosystem is complex. The fungus is just one part of the chain. It sits at the end of the line. It consumes what others leave behind. Sooty moulds do not harm the tree directly. They can block sunlight if growth is heavy. But the tree usually survives. The impact is cosmetic rather than fatal. In some cases, the black coating can be washed off by heavy rain. The water cleans the leaves. The fungus returns when the honeydew flows again. The cycle is persistent. The presence is constant. In New Zealand forests, sooty moulds are everywhere. Look at the leaves of any beech tree. You will see the black coating. It is a sign of a complex relationship. The tree provides the sap. The insect extracts it. The bird and wasp consume the waste. The fungus grows on the residue. Each player has a role. The fungus is the cleaner. It removes the excess. It turns waste into biomass. The forest floor benefits. The air remains clear. The balance is maintained. The name reflects the appearance. It is soot-like. It is dark. It is pervasive. The fungus does not seek attention. It simply grows where the food is. It does not care about the tree's health. It cares about the honeydew. The availability of sugar drives its spread. The insect population determines its success. The bird population influences the insect numbers. The web is tight. The connections are vital. That is the sooty mould. Black, powdery, and ubiquitous. A fungus that lives on waste. It carries on.