Pests & diseases


So far as I am aware my Eucalyptus haven’t had any diseases. Any loses have ultimately been down to severe wind burn or lack of hydration in one particular area where there is also a lot of shading during the winter.

Blue Gum Psyllid

Blue gum psyllid has been a continuing issue, though they’re controlled by spiders and earwigs. Ladybirds and Lacewings also predate on them.
I don’t spray with chemicals, and during the second year I noticed a huge increase in the number of earwigs which to my surprise turned out to have a voracious appetite for the larvae of blue gum psyllid 😁

I still get Blue Gum Psyllid, (they are endemic to Ireland) though each year there are less of them as the biodiversity of my small patch of land increases.

Some varieties are more susceptible than others. I’ve found NItens, Globulus, common name Blue Gum, so there’s a clue. To be particularly prone, though the Pulverulenta in the photo below can also become infested.

Blue Gum Psyllid on Pulverulenta

Psyllid are a sup sucker, a bug. If an infestation becomes chronic, then I go around with the garden hose on mist setting and wash them off.

It’s not so much the actual Psyllid that does any damage, but rather, they create a cotton wool like ball in which they lay their eggs. This encourages black mould which rots new shoots.

Blue Gum Psyllid Honey Dew wool

The eggs hatch into larvae

Blue Gum Psyllid larvae

Eucalyptus Leaf Eating Beetle

Chrysophtharta Cloelia

I started noticing these a year or so ago, 2023. I don’t get many, though they can be voracious.

Glossy shield bugs predate on them and I’ve seen a few of them on my patch. I think the other insect predators such as the earwigs will also predate on them, so I’ll stick to my no chemicals policy.

Eucalyptus Leaf eating beetle

Although this study of Leaf Eating Beetle is from Brisbane, Australia, it provides some generally useful information.

I won’t be spraying any chemicals, the damage to the wider ecosystem, the health damage to me personally, and my customers would be unacceptable.

There were experiments with wasps here in Ireland, though details were hard to get a hold of.

In my opinion the video below shows the option for controlling Eucalyptus pests.

I’m a big fan of the New Zealand forestry industry, a progressive approach to commercial timber production and responsible, broader environment management. A link to further information about Eucalyptus Leaf Eating Beetle‘s natural predators.

Trials of the parasitic wasp, Enoggera Nassaui have been carried out in Ireland, though its unclear from the research I’ve done whether the wasp is now widespread in the wild as of 2024.

The study linked to above is from November 2018