Eriococcus coriaceus is a common pest of Eucalyptus trees, particularly E.globulus in plantations. The oval sac covers the body of the wingless female. The female lays hundreds of eggs within the sac. There is always an opening left at the end to allow nymphs to leave the capsule. The honeydew exuded by the insects often causes a black sooty mould to grow on the leaves which can affect photosynthesis. There are many natural predators and parasites of this species. These include ladybird beetles and parasitic wasps.
Eriococcus coriaceus
Late December 2004
Knocklofty Reserve, nipluna/Hobart
Photo KE
Late January 2012
kunanyi/Mount Wellington
Photos AD
Late December 2024
Lenah Valley
Photo KE
Early August 2016
Knocklofty Reserve, nipaluna/Hobart
Photo KE
Mid March 2018
Knocklofty Reserve, nipaluna/Hobart
Photo KE
Various aged colonies on a Eucalyptus globulus
Late August 2020
Knocklofty Reserve, Hobart
Photos KE
Early March 2021
Tasmanian Bushland Gardens
Note that they are being predated upon by the larvae of the gumtree scale ladybird Rhyzobius ventralis
Photos KE
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Mid March 2021
“Inala”, Lunawanna, Bruny Island
Photo KE
Late September 2022
Richmond
Photos KE
Mid January 2023
Sisters Beach
Photos KE
Different stages on a small Eucalypt
Mid January 2024
Ulverstone
Photos KE
References
CSIRO, 1990. Insects of Australia, Volume 1: A Textbook for Students and Research Workers. 2nd Edition. Melbourne University Publishing.
Forest and Timber insects of Australia No 22. https://www.scionresearch.com/__data/assets/pdf_file/0018/3951/Ent22Eriococcuscoriaceus.pdf Accessed September 18, 2016