The balga Xanthorrhoea preissii, a grass tree, is a striking part of our bush that was use by Noongars for medicine, tools and sustenance. Grass trees are monocotyledons but neither grasses nor trees.
 Carbon dating has found grass tree ages of up to 1,000 years. Also, they have special contractile roots that pull seedlings underground so that plants on sandy soils may not develop an above ground stem for 10 to 30 years. I reckon that the five-metre plant I found in Candy Block must be ancient. Unfortunately, twenty-eight parrots are now attacking its new growth.
 
The grass tree at Foxes Lair is the smaller Xanthorrhoea brevistyla that lacks an above ground trunk. It is an insect magnet when flowering in November.
 
I regularly see severe insect attack on balga flowering spikes and brought one home for examination. The green stem had frequent reddish- brown sunken lesions with gum exuding from small holes. The split stem revealed tunnels containing bardi grubs, surrounded by reddish brown fungal infection. Once again, a canker fungus that affects eucalypts and other shrubs

Interestingly, a previous investigation on wandoo crown decline in Foxes Lair  found a similar combination of insects and fungus. The fungus causes severe damage to trees and shrubs. Fungus doesn’t seem to affect the balga trunk, presumably because flowering spikes naturally die before it can spread further.
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​The bardi grubs are larvae of longicorn and cockchafer beetles. They have tunnelled up through the entire flowering stem.
The flowers and seeds were attacked by a brownish caterpillar that eats them under a protective cover it makes from its frass (poo) and silk.

​Last year I received a shock when one of two apparently healthy balgas that I had photographed earlier snapped off at mid stem

​The centre of a normal trunk is filled with living fibrous material above a woody cone-shaped base that remains long after a plant has died. The living centre is surrounded by old leaf bases held together by natural resin, which provides support and excellent fire protection.
The fibrous centre of the dead balga was completely replaced by a soil-like material containing wireworms, which were attacking the interior of the surrounding leaf bases

​As Noongars ate bardi grubs that were in the centre of dead balgas, I suspect that they had chewed out the living material before wireworms moved in.
This balga had been surviving with a decayed centre for some time until the weakened stem snapped. It is a natural process and dead remnants can be attractive in their own right.
 
Unfortunately, increased in Australian ringneck parrot (twenty eight) numbers are causing premature balga death from them continuously chewing the new growth.

Greetings Fellow Foxies,
​​Yesterday I noticed honeybees clustering around cracks in a single Marri tree. My first thought was that the bees must be pretty desperate to drink the astringent reddish kino that oozes out of marri trunks and branches (kino was used by Noongars as an antiseptic and for treating stomach disorders).
 
It then dawned on me that I was surrounded by marris covered in kino deposits but the bees were only on one tree trunk. The following images reveal my discoveries as I peeled away about a centimeter of layers with a pen knife.
​​After shooing off bees and removing an outer layer of loose dead bark, I discovered droplets of honey-coloured sweet nectar oozing out with surrounding bark stained black and bright blue in one case, by a skin fungus growing on nectar-rich bark.

A bit further in was a tiny (3mm long) cigar shaped object at the top of the flow. This is an insect pupa (note the head and remnants of legs on the pupa case), that was still in the soup stage prior to reforming as an adult. Judging by the copious nectar flow, it is likely that the pupa had drowned.

​Further in was a defined oval hole of a burrow that opened out into a frass (poo) filled chamber right on the boundary between the bark and sapwood. This cambium layer contains the tree’s plumbing system where water (going up) and sugar solution (going down) is situated.
 (Random comment: this is why trees die when they are ringbarked).
 
When I mistakenly penetrated the sapwood, red kino immediately welled out and started to become gummy.

The conclusion is damage by a beetle or moth larva  borer that specifically targets the marri cambium layer causing sugars produced by the tree to flow out as nectar.
 
Large deposits of red kino on marris comes from damage to the underlying sapwood as described in this blog
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​Greetings Fellow Foxies,
A year ago I spotted a wandoo in Candy Reserve that had large strange pits in its trunk and didn’t think too much about it until I found another example in another reserve. In this case a large branch had fallen an affected tree many years ago, leaving beautifully patterned wood after the bark had fallen off.

​Pits on the living tree are like inverted oval cones, and the damage extends up the tree to the youngest branches.

​On close examination I could see the tree’s annual growth rings on the sides and a small hole in the heartwood at the base. The sapwood was clean and clear of fungi indicating that an insect was the primary cause.
When I cut a section trough a pit I found a small (about 3mm diameter) burrow leading from the base into a more extensive gallery system in the middle of the stem.

Enquiries have failed to produce an identification
There are similarities to wandoo crown decline as fungal canker was present in the heartwood but there are clear differences.

• This is very rare and hasn’t spread to any adjoining trees.
• The sapwood is healthy.
• I could see a ring of chew marks on the outermost sapwood layer surrounding pit which suggests that some insect comes out of the basal burrow to feed regularly.
• There must be successive generations of the insect, as indicated by the growth rings in the pits and the continuation of damage on the youngest branches

 Apart from cutting down a 200 year old tree or camping out by it and do nightly inspections, I can only ask if any of my readers can help solve this intriguing mystery
For more images click HERE

Greetings fellow Foxies,
 Have you noticed large numbers of dead leaves on local wandoos, particularly where a whole twig or small branch has died?
This condition where wandoos die back and leave dead branches projecting though the leaf canopy is called Wandoo Crown Decline. This is a cyclical problem that caused huge damage in the 1990’s when the Wandoo Recovery Group was formed.
Research showed that boring insects and associated pathogenic fungi, are the principal agents disrupting stem nutrient and water conducting channels. Symptoms are worse in dry autumns, but underlying factors driving the long term cycle are unresolved.
This autumn I couldn’t find any pattern of areas affected. There are a couple of monitoring sites in Foxes Lair that don’t appear to have a lot of very recent damage. Affected trees in Foxes Lair seem to be randomly distributed, but badly affected ones have obviously been repeatedly attacked.
Being a loyal citizen scientist, I nipped out and sampled a couple of branches from a badly affected tree for close analysis.
My first observation was that the branches were distorted and gangly with lots of dead lower shoots, stems with dark cankers (sunken dead lesions) and resprouting shoots. Clearly not a single year problem.
Looking closely, it was amazing to see so many things attacking the tree. I found stem and leaf galls, and leaf damage from a range of chewing insects, but the real cause of branch death is inside the stems.

The insect involved is a jewel beetle Cisseis fascigera). Beetles emerge from November to February, mate and lay eggs on stems. The larva that looks like a witchetty grub chews tissue and wood inside and along the stems (longitudinal galleries), before pupating in its gallery and emerging a year later.
Unfortunately the insect introduces spores of rot fungi that spread through the stem.