Do your eucalypts look like they are dying?
06 June 2016
You may have noticed that large sections of eucalypt trees around Mudgee, Gulgong and Goolma look like they are dying. The good news is that the trees are not dying. The bad news is that they are under attack from a small insect called a Psyllid. The psyllid currently attacking our trees belongs to a genera called Cardiaspina.
A psyllid is a jumping plant lice that sucks the saps from the leaves of eucalyptus trees. A closer look at the leaves of the trees reveals what seems to be a white scale. This scale is in fact a lerp. Lerps are the sugary coatings that act as a protective cover for the psyllid. It helps protect it from its enemies and dehydration.
Every group of eucalyptus tree has its own group of psyllid species. It is natural for populations of eucalyptus trees to come under attack from psyllids in a cyclical nature.
Most eucalypts can cope with high psyllid numbers for a couple of seasons and will recover once the population of the psyllid declines. Outbreaks will often last 2-3 years with several cycles of defoliation and recovery during this time.
Outbreaks are often recorded after significantly dry periods which put the trees under stress and lower their natural defences. With the exceptionally dry and hot February and March at the start of this year many of the trees would have been suffering severe dehydration. This makes them susceptible to attack from the Cardiaspina.
The populations of the psyllid will eventually collapse due to changes in the weather conditions and the depletion of suitable foliage. When this happens the psyllid is also more vulnerable to natural predators including: wasps, ladybird larvae ants, spiders and birds such as honeyeaters thornbills, pardalotes and rosellas.
If you would like more information on controlling the psyllid please contact Bruce Christie or Julie Reynolds at the Mudgee Local Land Services office on 6378 1700 or 112 Market St, Mudgee.
Media enquiries: Kylie Krause | 0439608370