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10 | April/May - 2017 | 11
In the following pages, Potatoes Australia provides readers with a detailed feature on the highly destructive
pest, tomato-potato psyllid (TPP) and its implications on the Australian potato industry. To begin, we share an
overview of TPP and the bacterium it vectors (Candidatus Liberibacter solanacearum), which causes zebra
chip disease in potatoes.
Following the recent tomato-potato psyllid incursion
in Western Australia, Horticulture Innovation Australia
has engaged the Australian potato industry to provide
immediate funding from the fresh and processing
potato levies, vegetable levies, as well as funds from
the Australian Government to support industry efforts
in managing the incursion.
TOMATO-POTATO PSYLLID: A DESTRUCTIVE POTATO PEST
SUPPORTING AUSTRAL IA’S
POTATO GROWERS DURING
AN INCURSION
The discovery of tomato-potato psyllid (TPP; Bactericera cockerelli)
in a Perth vegetable garden in February triggered widespread
surveillance in commercial crops and backyard gardens in Western
Australia, and placed the $480 million-a-year Australian potato
industry on high alert.
TPP also vectors the bacterium Candidatus Liberibacter
solanacearum (CLso), which causes zebra chip disease in potato crops.
PSYLLID ORIGIN
TPP is an insect from the United States that spread to New Zealand.
It was not considered a major pest in the United States until 1999,
when it began to spread from Mexico into California and Texas due
to the emergence of a new, more invasive biotype of the psyllid. It
was this biotype that was introduced to New Zealand in 2005-06,
most likely on smuggled chillies from California.
It is believed that TPP arrived in New Zealand in 2006. A confirmed
identification was made in May 2008 in Auckland, but by that point it
had spread to many tomato glasshouses in the Auckland area.
In 2008, the initial outbreak in three Auckland glasshouses
cost growers NZ$1 million, with the cost to industry growing
exponentially from there.
INSECT DESCRIPTION
TPP is a tiny sap-sucking insect that is black with a white stripe on its
back. Adults resemble small winged cicadas and are about 3mm long.
It primarily feeds on potatoes, tomatoes and capsicums, but
can live off, or at least shelter on, a large number of other plants
(approximately 20 plant families). Other hosts that are preferred by
the psyllid include additional solanaceous crops (eggplants, chilli and
tamarillos), sweetpotato and weeds, such as nightshade and boxthorn.
A clear indicator of the psyllid’s presence on a crop is the crystals
of honeydew that the young (nymphs) produce. These are a waste
product that looks like caster sugar and are found on the leaves of
an infested plant. The nymphs are small, oval and green-yellow in
colour while the adults are likely to jump off the plant if disturbed
and, as such, are more difficult to see.
The first response funding following the detection of tomato-
potato psyllid (TPP) in Western Australia was used to engage a key
researcher from Plant & Food Research New Zealand to deliver
possible responses to the incursion in regards to monitoring
and control of TPP, as well as information on Integrated Pest
Management and long-term management planning.
Horticulture Innovation Australia is continuing to seek advice
from both the fresh and processing potato Strategic Investment
Advisory Panels (SIAPs) into additional areas of R&D investment
in managing this incursion, in particular around management and
surveillance of TPP. This is being done in consultation with other
industry state and national bodies, which have the responsibility
for implementing response arrangements.
Horticulture Innovation Australia continues to work closely with
AUSVEG, other industry bodies and levy payers to determine the
best strategy for funding to be used with the greatest impact in
managing biosecurity issues.
BOOSTING NATIONAL BIOSECURITY
In addition, the nation’s seven plant Research and Development
Corporations (RDCs) recently announced a new partnership
approach to strengthen the nation’s biosecurity. Headed up by
Horticulture Innovation Australia, the new initiative will increase
research coordination, reduce duplication and fill gaps in plant
biosecurity R&D.
The initiative will also create better linkages between industry
research and the national biosecurity systems managed by the
Australian and state and territory governments.
“To date, Australia’s approach to managing research investment
and delivery for our plant industries has been fragmented and
lacking coordination. This is simply because the biosecurity space
is incredibly complicated, crossing more than 50 commodities,
all states and territories, and countless stakeholder groups,”
Horticulture Innovation Australia Chief Executive John Lloyd said.
The group has developed a list of principles for guiding plant
biosecurity research to ensure the development of a successful
cross-sectoral approach. These principles will be used to
coordinate plant biosecurity research and development decisions
across all RDCs.
ZEBRA CHIP SYMPTOMS
While zebra chip disease has not been detected in Western Australia
at the time of writing, it is still important to monitor crops and keep
an eye out for indicators of the bacterium CLso, as zebra chip
disease can significantly reduce the yield and health of potato
crops and render potatoes unsaleable.
Foliage symptoms in potato plants include stunting, chlorosis
and swollen nodes, causing a zig-zag appearance of the upper
growth, a greater number of auxiliary buds and leaf scorching
leading to early dieback.
Zebra chip can affect fresh, processing and seed potatoes in
different ways. Symptoms are less severe for fresh potato, but
there is a reduction in yield.
In processing potatoes, the infection causes a brown discoloration
in the potato, which is more noticeable when it is fried. This results in
rejection of the crop, as they cannot be used for chips because
of the ‘burnt’ appearance and a perceived effect on taste.
ADVICE FOR GROWERS
Growers who suspect that TPP may be present in their crop need
to report this to the Exotic Plant Pest Hotline on 1800 084 881.
In Western Australia, growers can also use the Department of
Agriculture and Food, Western Australia (DAFWA) MyPestGuide
reporting app. Details about how to access and use the app are
available at . DAFWA has also developed a video
that provides guidelines for psyllid detection. This video, and
associated fact sheets, can be found on the AUSVEG biosecurity
web page at
For more information, contact AUSVEG on 03 9882 0277 or email
.
This communication has been funded by Horticulture Innovation Australia
Limited using the research and development Fresh Potato Levy and funds
from the Australian Government.
Project Number: PT15007
For more information, please visit or contact Hort Innovation
Relationship Manager Christian Patterson on 02 8295 2382 or 0433 896 753 or
email .
This communication has been funded by Horticulture Innovation Australia Limited
using the research and development Fresh Potato Levy and funds from the
Australian Government.
Project Number: PT15007
INFO
INFO
R&D | PEST OVERVIEW | TPP FEATURE TPP FEATURE R&D | INCURSION RESPONSE |
An adult tomato-potato psyllid with the moulted ‘skin’ of a
nymph. Image courtesy of Plant & Food Research New Zealand.