Foxes Lair
  • Home
  • About
    • About Foxes Lair
    • History
    • Landscape and Soils
  • Things To Do
    • Scavenger hunt
    • Picnic Spots
    • Walking Tracks
    • Visit the Arboretum
    • Geocaching and Orienteering
    • Ride Your Bicycle
  • Things To See
    • Birds
    • Wildflowers
    • Trees in the Narrogin district
    • Narrogin spiders scorpions ticks
    • Vertebrates
    • Fungi and lichens
  • Other Places to Visit
    • FAMILY bush attractions
    • WILDLIFE bush attractions
    • WILDFLOWER bush attractions
    • all reserves
  • Foxes Lair seasonal guide
  • 1Foxypress
    • Foxypress
    • Vanishing Farms
  • Contact

Dry season shrub death- drought or other causes

7/3/2020

0 Comments

 
PictureScattered pattern of Dilwynnia laxiflora death
​ Greetings fellow Foxies,
 
There have been many comments recently about widespread shrub death in Foxes Lair due to the exceptionally dry spring and summer.
Certainly, there is more death than usual, but this doesn't explain the scattered pattern in Foxes Lair with dead plants next to healthy ones.
Luckily my esteemed colleague Detective Doug volunteered to investigate this problem.
 
The great man randomly selected two each of dead and healthy Dilwynnia laxiflora (pea flower) plants for examination

​Dead plants.
The roots were very bent and thickened, particularly the tap root that snaps easily. Borer channels were on both the outside and inside, including one that contained a jewel beetle emerging from its pupal case.
Picture
Thickened fissured root crown
Picture
Jewell beetle larva inside root crown
Picture
Jewell beetle nearly ready to emerge from pupal shell
 Problem solved?
No, being a true scientist, Detective Doug insisted on also examining the healthy specimens
Roots of both live plants had also  been attacked, although to a lesser extent than dead plants.
The first plant had a few minor lesions but otherwise appeared normal. However when split in half lengthwise the root was hollowed out and contained a hibernating? jewell beetle. These beetles are common on pea flowers in October so presumably they hibernate until spring.
Picture
Picture
The second healthy plant showed evidence of insect attack that appeared to be confined to the surface. However, when cut in half it was obvious that insects had entered and tunnelled up the centre of the root. While doing this they brought in spores of a canker fungus, shown by the blackened areas. This fungus invades healthy tissue, blocks water and nutrient transport and kills the plant. 
​
Conclusion
These plants are routinely attacked by borers and may survive for more than a year until invading canker fungus kills them or they snap off. Increased water stress from extended dry weather hastens plant death.
Case closed
​
Interestingly, a previous investigation on wandoo crown decline in Foxes Lair  found a similar combination of factors.

Picture
Healthy plant, minor external damage
Picture
root interior showing borer channels infected by canker fungus
0 Comments



Leave a Reply.

    Author

    Doug Sawkins is a friend of Foxes Lair 

    Categories

    All
    Animals Other
    Birds
    Disorders Plant Animal
    Fungi Lichens
    History
    Insects Bugs Other Arthropods
    Landscapes Soils
    Other Reserves And Places
    Reptiles
    Spiders Other Arachnids
    Tree
    Walks Other Facilities
    Wasp
    Wildflowers Orchids
    Wildflowers Other Summer Autumn
    Wildflowers Other Winter Spring
    Wildflowers Parasitic

    Archives

    December 2022
    October 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    January 2022
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    November 2019
    October 2019
    July 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    September 2018
    July 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    July 2017
    May 2017
    April 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    September 2014
    August 2014
    April 2014
    March 2014
    February 2014
    May 2012
    March 2012
    October 2011
    September 2011
    August 2011
    April 2011

© 2015 All Rights Reserved. Doug Sawkins, Australia.