Q.Eucalyptus approx 8 metres high, approx 30 years old
In the last 4 months I noted bark coming loose from trunk. A while later it started to fall off exposing some red/ black weepy looking patches going up the trunk; some branches at this stage had started to lose leaves and some small branches died. Approx 3 months ago we removed some soil around base as we found ants nesting there and obviously interested in the oozing matter. We treated the ants. Since then some branches have put out new growth and is at present showing buds forming. Though another branch is showing more red/black matter appearing. What product and other action can I use to attempt to control problem’? I can take photo and email direct or as message.
It appears that you have an "ironbark", like Eucalyptus sideroxylon or possibly another species.
The bark peeling can be natural shedding as the inner bark develops and the outer bark peels off, or it can be due to an injury.
The red substance is also a natural, oxidized sweet sap exudation and is called "kino". It dries dark red or black. The ants will be attracted to feeding on the sweet kino.
Unless there is wounding that compromises the structural integrity of the tree, or pest activity other than the ants, then this should not be considered a disease condition, but rather the tree's natural defense mechanism and exudation of protective substance.