What is Mistletoe?
Mistletoe is a semi-parasitic plant that grows on a host tree or shrub. The Mistletoe gets its water and nutrients from the host plant but produces its own energy through photosynthesis. Some Mistletoes are epi-parasitic and only grow on other Mistletoes.
Mistletoe infestation - Thornell's Reserve Longwarry North |
Many Mistletoes very obviously use eucalypts as their host tree however many Mistletoes parasitize acacias, casuarinas, banksias, angophoras, melaleucas and numerous other native Australian trees and shrubs.
There are over 90 species of Mistletoe in Australia and nearly all of them are endemic. Mistletoes can be found on all continents except Antarctica and worldwide there are more than 1500 species.
What benefits do Mistletoes provide?
Mistletoes generally have long flowering and fruiting seasons. Because the roots are tapping into the host plant, Mistletoes can flower even through dry times, making them a dependable nectar and fruit source for fauna species when little else is available.
Mistletoes provide habitat for a wide range of fauna, especially birds, possums, bats, gliders and insects. These animals using Mistletoe as a resource are often themselves important pollinators in the broader ecosystem. More than 30 bird species are known to feed on Mistletoes and over 200 bird species have been recorded nesting in Mistletoe.
The caterpillars of many Australian butterflies use Mistletoes for a food plant.
Imperial White butterfly emerging from its pupal stage on a Mistletoe plant |
How are Mistletoes dispersed?
Research has shown that Mistletoes rely principally on birds for pollination and seed dispersal. The Mistletoebird is one of the main seed dispersers of the plant.
Male Mistletoebird |
Do Mistletoes kill trees?
Mistletoes do not kill healthy trees. Mistletoes rely on
their host tree for their own survival. Some trees are capable of defending
themselves from Mistletoe infestation by dropping infected limbs.
In general, trees with Mistletoe will die due to a range and combination of health factors – soil compaction or erosion, dieback, salinity, fire, drought, persistent inundation, etc.
Dead Mistletoe on a struggling host |
Mistletoes are not resistant to fire in the way that many native trees are. Bushfire in fact can be seen as a cleansing agent in regard to Mistletoe infestation.