We have many huge Moreton Bay fig trees in our school yard in Brighton, Melbourne, one of which is in the Kindergarten playground. The tree suffers from a disease usually at this time of year (March/April). They say it is caused by stress. It is the only one on the grounds that has this disease. It causes the leaves to fall and on them is a sticky substance not unlike chewing gum. This year the sticky gum is dripping from the leaves of the tree as well as falling with the leaves. This creates a terrible mess on the shoes of any passer by particularly the shoes of the kindergarten children who play around this tree. In the past the gardener has injected the tree with a chemical substance but because it is a poison it has to be done in the holidays when the children are not present. Many bats visit the trees throughout the year and we have been told they also contribute to the cause of the disease. It is a magnificent tree and we love it but it causes us grief. It is classified by the National Trust as many of the others are. What is the cause and what is the cure? Any advice? Jane Britten, Head of Junior School

Reply to post by Jane Britten , on March 18, 2001 at 23:04:48:

So far I've found reference to one particular insect that may feed severely on the leaves of this tree: the rubber tree pysllid, Mycopsylla fici.
Unfortunately we humans set up beneath large trees to gain the benefit of shade, only to damage the soil and root system by compaction. I wonder if the heavy use under this tree is what sets it apart from the others that are not so aflicted with the "disease".
I usually think of insect-prone trees as being under some other stress already. While one may try to control the insects, is the underlying stress recognized and addressed? Perhaps the tree is in need of protection. But that is probably not convenient or easy to arrange.