When is an apple, not an apple?

Apple galls

On our latest field trip, we came across these funny looking growths on the fresh eucalypt regrowth along the burnt ridge of the Mt Mathieson track. Questions were asked and other than that they were galls made by small insects nothing else was offered.

Recently I've been reading some of our old newsletters and the words of one of our contributors came to me - “…the impulse to know, to want to learn, to discover for one’s self,  .... in other words one gets caught up in the excitement of discovery.” This was me in a box. I wanted to know more about these galls.

Searching the www finds a little information though usually quite academic but I was hooked. I was caught up in the excitement of discovery. 

More apple galls

The type of gall depends on the parasite that produces it. They can be wasps, beetles, midges or something even smaller such as viruses, fungi and bacteria. The insect parasite lays her egg in the plant which forms a protective, woody growth around it. Hence a gall. Psyllids, tiny sap-sucking insects related to lerps, cause galls on native trees. Schedotrioza spp. form distinctive spherical “apple” galls on eucalypt leaves.

Psyllids are approximately 4 mm long and hold their wings roof-like over their bodies and look a little like miniature cicadas. The immature psyllids are specialist feeders, with many species restricted to one plant type or even a single species of plant, and often to particular parts of the plant (leaves, new shoots, etc.) or growth stages (either young or mature foliage). Adults disperse over short distances by jumping or flying, but many species may travel long distances on air currents.

Apple Gall through a Eucalypt leaf

Webliography:

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/sternorrhyncha

http://oneminutebugs.com.au/gall-inducing-insects/

http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0007/390283/Psyllids-Insect-Pests-of-Eucalypts.pdf

http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0007/390283/Psyllids-Insect-Pests-of-Eucalypts.pdf 

Mt Mathieson Trail Reconnoitre

The leader and I went to check the Mt Mathieson Trail for the July outing on Friday. 

Grasstree spikes on a burnt ridge, Mt Mathieson

It was beautiful weather, warmer than usual for this time of the year. We only went as far as the Lookout, about 2 km. It was upsetting to see how bushfire damaged the area was. A phantom of its former glory. 

Yes, shoots are coming back on the trees and the Xanthorrhoea (grasstrees) are looking healthy but so little canopy and few birds. By the time of our outing the grasstree flower spikes should be fully out. Already some of the early bloomers were attracting bees and butterflies.

Large Grass-yellow on grasstree flower spike

Not all the grasstrees survived however. The one below had this fungi growing on its rotting stem. Don't know which species of fungi it is.

Fungi growing on burnt grasstree

Although fire-ravaged it was a lovely walk with amazing views at the lookout and plenty of birdlife in the thicker scrub. I'm looking forward to our return on Saturday July 18. See previous post for details.