Spread of thrips diseases to the Pacific islands

April 2016. Australian scientists are looking at the possibility that winds cold carry phyllids from New Zealand (see below) across the Tasman to Australian and beyond. A member asked a question about the possibility of IPM being used to control the psyllids should spread occur.

This was the reply from a scientist with Plant & Food Research.

(1) Some crops are more susceptible than others. Some chilli varieties do not need to be sprayed with insecticide. Yet it is impossible to have complete loss of unsprayed (and even sprayed) potato and tomato crops! So, grow tolerant crops, be it chilli, capsicum and eggplant, rather than tomato or potato crops.

2) There are very important naturally occurring foliage dwelling predators of TPP in New Zealand. They are brown lacewing (Micromus tasmaniae) and a hoverfly species (Melanostoma fasciatum, called small hoverfly). Plus spiders are important predators on seedlings. In New Zealand, there may be up to 200 predators per large plant (mainly hoverfly eggs and larvae) and they can control all small pest infestations such as TPP, aphids, thrips and small caterpillar pests. So, grow crops and border crops that are good reservoirs for these important predators. Lacewings do not require a major reservoir crop, but hoverflies do. Plant long-flowering crops near commercial crops to get much higher populations of hover fly larvae in the crop. Also, predators thrive on potato plants, but are not common on tomato plants (predators don’t like the hairy leaves of tomatoes).

3) There are also some insecticides that are recommended that have less impact on important natural enemies; they are used when action thresholds are exceeded on tomato and potato crops.

ABC Rural
http://www.abc.net.au/news/2016-04-12/researchers-study-likely-wind-paths-for-potato-psyllid/7317084

Potato industry studies winds that could carry damaging insect from New Zealand

Vic Country Hour ByDavid Sparkes 9

Updated Tue at 3:16pm

Photo: Australia’s potato industry is on the lookout for a disease-carrying insect that could arrive from New Zealand. (Cate Grant: ABC News)

Trade winds or cyclones could potentially carry a disease-carrying insect from New Zealand to Australia, posing a threat to Australia’s potato industry.

Australian researchers say strong winds could carry the tomato potato psyllid across the Tasman Sea.

A new project is hoping to identify the most likely pathway.

AUSVEG spokesman Shaun Lindhe said the psyllid carries zebra chip, a disease which would damage potato crops if it arrived in Australia.

“[This research is about] having information about these natural pathways,” he said.

“We’ll be able to provide greater detail for modelling and it will be good to have more accurate information on the timing of winds coming to Australia and their point of origin.

“It will give [farmers] the information they need to know what time of year they should be looking or testing for diseases.”

Mr Lindhe said the tomato potato psyllid does not currently exist in Australia.

Zebra chip disease damages the yield and health of potato crops and renders potatoes unsaleable.

The researchers are working in conjunction with the potato industry as part of a three-year Plant Biosecurity Cooperative Research Centre project.

The tomato potato psyllid’s potential arrival from New Zealand is one of three such scenarios being examined by the project.

The other two are airborne pathways from Indonesia and Papua New Guinea, which could carry different psyllids affecting the sugar and citrus industries.

Topics:rural,pests,agricultural-crops,vegetables,horsham-3400