The Pine aphid, a devastating pest that causes more than $20 million in lost wood production to the softwood industry each year, is under pressure from a biological control taking hold in pine growing regions across NSW. Source: Timberbiz
Ongoing monitoring by Department of Primary Industries (DPI) scientists is determining how widely established the biological control, which is a tiny wasp from California released here in 2009, has become in NSW commercial pine forests.
“To date, established populations of the biological control wasp have been found in the South West Slopes (Tumut/Tumbarumba), Central Tablelands (Bathurst/Orange) and the Northern Tablelands (Walcha),” said DPI principal research scientist Angus Carnegie.
“It’s a very encouraging sign that we have found the biocontrol wasp has spread naturally into new areas since its release.
“The wasp has now established in three of the five major NSW pine growing regions and is looking like the most cost-effective longterm option for reducing the incidence of damaging pine aphid,” he said.
“We have evidence of the wasp spreading more than 20km in a year in some instances so the process will take time but it is happening.”
Dr Carnegie said the pest Monterey Pine Aphid was first detected in Australia in 1998 and is now affecting all pine growing regions of the country.
“Feeding by the aphid causes needles to turn yellow and prematurely defoliate, with trees over 15 years old tending to be more severely damaged.
“In 2006 and again in 2007 over half of the NSW plantation estate, some 100,000 ha, was damaged by the aphid.”
Dr Carnegie said NSW has the largest pine plantation estate in Australia, the majority managed by Forestry Corporation of NSW.
“The Forestry Corporation plantation estate is surveyed annually for forest health by DPI scientists, who also provide technical expertise on pest and disease management, diagnosis and research.
“In 2006, the forest industry funded a biological control program that identified the parasitic wasp, Diaeretus essigellae, from California as a strong biocontrol candidate.
“This wasp lays eggs inside aphids as they feed on pine needles, ultimately taking over the aphid and emerging weeks later and flying off in search of more aphids.
“Release of essigella biological control wasp across Australia began in 2009 and included all pine growing regions of NSW.”
DPI Forest Health staff has conducted release and monitoring for establishment in NSW with funding from Forestry Corporation of NSW.
It is important to note that the tiny wasp is not a species that readily stings humans and it is not harmful to humans.
