Issue number: 23Date: 17/10/2014

PestFaxPestFax is a weekly informative and interactive reporting service, providing risk alerts, current information and advice on pests and diseases threatening crops and pastures throughout the grain

belt of Western Australia (WA). PestFax is supported by the Grains Research and Development Corporation (GRDC) and promotes national pest management information and Integrated Pest Management (IPM) principals.

Newsletter of the Department of Agriculture and Food, Western Australia (DAFWA).

ContentsStored grain pestsNative budworm

To view a map of pest and disease reports, see PestFax Map and PestFax newsletters for back copies of PestFax. If you have recently observed or heard news of insect or disease pests in crops and pastures contact PestFax@agric.wa.gov.au or use the online ‘make an on-line report’ link.

This is the last issue of PestFax for the 2014 growing season. Extra editions may be circulated if extraordinary circumstances occur. PestFax will resume weekly issues in autumn 2015.

Stored grain pestsGrowers who are yet to commence harvest are reminded that they should check and maintain grain silos before storing this year's harvest to guard against grain storage pests. Regulations prohibit the sale and handling of insect infested grain and the spraying of contact insecticides onto grain, other than malathion to stored grain.

DAFWA Entomologist Rob Emery says that sealed silos are the preferred system of storage but rubber seals should be checked. Augers, field bins and silos should be thoroughly cleaned of grain residues and treated with a hygiene spray or dust. The ground around storages should be cleared

Supporting your success

of weeds and rubbish to prevent harbouring insects. Old grain resides should be burned or deep buried.

Be aware of withholding periods if you are treating the inside of an empty silo with a suitable insecticide such as malathion or fenitrothion, to provide residual control before the grain is loaded. Non-chemical products like Dryacide® dust need at least two weeks to be effective.

Dryacide is an insecticide and will provide good control for at least 12 months.  It is a non-toxic, diatomaceous earth product that must be applied when loading the silo at a rate of 1 kg / tonne.  This grain can only be used on your own farm since most central grain buyers will not accept it because it changes the flow characteristic of the grain. However you can store grain even in an open shed very safely using Dryacide.

Fenitrothion is a contaminant in exported grain. If you are using either liquid or dust in the weeks prior to harvest it is recommended you leave it in place for 2–3 days, and then wash it off to prevent contamination of any grain that may come into contact with the sprayed surface. It is better to have applied fenitrothion to an empty silo at least two months before harvest to allow it to degrade to harmless substances.

Rob says that phosphine is a very effective fumigant gas for sealed storages but it must be held under gas-tight conditions at a lethal concentration for 7-10 days to kill all insect growth stages. Poor fumigation can result in only adult and larval insects being killed giving the mistaken impression that the fumigation was successful. However, the immature eggs and pupae will not be killed so infestations will likely build up again quickly, selecting for resistant populations.

Insect populations with weak phosphine resistance have developed in all grain-growing states of Australia largely as a result of poor fumigations. Strong resistance is widespread in the eastern states so to help prevent the development of strong resistance to phosphine in Western Australia, use well maintained sealed silos.

Detecting phosphine resistant grain pests early will make eradication possible and will protect your income. To arrange a free resistance test for grain pests contact Nuccia Eyres or David Cousins (stored grain insect group, DAFWA, South Perth) on +61 (0)8 9368 3920.

Farmers keeping grain on farm for their own use, with silos that are not sealed can use aeration or Dryacide or a combination of both as alternative methods to keep insects in low number.  Aeration is a tool for creating a low temperature in the silo so that insects breed very slowly. Insects rely on the environmental temperature for body warmth and breed faster in warm conditions. If the temperature is kept below 20°C they will produce less progeny in the storage period. However to stop reproduction, grain temperatures must be kept below 14°C ; temperatures below 10°C (difficult in WA) will eventually kill the insects. Failure to follow these strategies may result in the grain having populations of insects and cannot be sold off-farm without fumigation by transferring it to a fully sealed and tested silo.

For more information on stored grain management techniques visit the GRDC supported website storedgrain.com.au and DAFWA webpages sealed silos make sense and insect pests of stored grain

Native budwormMost of the volunteer farmers and Department staff who have been trapping this season have packed away their traps because crops are too advanced to be troubled by future moth egg laying. Their efforts in sending in weekly reports to PestFax and providing advanced warning of the budworm threat is greatly appreciated by readers.

All late maturing pulse, canola and legume pastures should be checked for budworm, especially in areas where moth numbers have been recorded 3-4 weeks ago, refer to Native Budworm Moth Numbers 2014.

For information on insecticide withholding periods refer to PestFax Issue 20 26/09/2014 For information on native budworm reports see PestFax map and previous issues of PestFax Issue 21, PestFax issue 20, and PestFax issue 19.

For further information on native budworm visit the DAFWA webpage: Management and economic thresholds for native budworm.

Pesticide options for the control of native budworm can be found in the Winter/Spring Insecticide Spray Chart 2014 .

Also available:List of registered insecticides A list of registered insecticides to control winter/spring pests on canola, lupins, cereals, field peas and pastures is available on the PestFax webpage: Winter/Spring Insecticide Spray Chart 2014

A list of registered insecticides to control autumn/winter pests on canola, lupins and cereals is available on the PestFax webpage: Autumn Winter Insecticide Guide 2014

Crop insects: the ute guide This book covers crop pests, beneficial insects, biological control, grain storage pests and biosecurity pest threats specific to WA. Copies are available from some DAFWA offices for a cost of $10.00 or by mail order by phoning the DAFWA South Perth office on +61 (0)8 9368 3710.

MyPestGuideDownload the App onto your mobile phone for convenient pest and beneficial identification, reporting and image recording: from the Google Play Store or the Apple iTunes Store. Click the links or search for “mypestguide”.

Free insect identification Having troubles identifying mites or other pests? For free identification, send your digital pictures (in focus) or live specimens (in a non-crushable plastic jar) to Peter Mangano or Svetlana Micic at the postal details below.

Svet Micic, DAFWA Albany 444 Albany Highway, Albany WA 6330Email: svetlana.micic@agric.wa.gov.au Phone: +61 (0)8 9892 8591 or +61 (0)427 772 051

Peter Mangano, DAFWA South Perth3 Baron-Hay Court,South Perth WA 6151Email: pmangano@agric.wa.gov.au Phone: +61 (0)8 9368 3753 or +61 (0)404 819 534

Integrated Pest Management Guidelines for grains

AgTactics and AgMemo Other regional DAFWA news updates are available on DAFWA website .

Seasonal climate outlook Seasonal climate outlooks are available on DAFWA website .

AGWEST Plant Labs Plant disease diagnostic services are located at the DAFWA South Perth office. For information on sending samples and charges contact +61 (0)8 9368 3721 or Fax +61 (0)8 9474 2658 or visit the DAFWA website or the AGWEST Plant Laboratories

This is the last issue of PestFax for the 2014 growing season. Extra editions may be circulated if extraordinary circumstances occur. PestFax will resume weekly issues in autumn 2015.

Important disclaimer The Chief Executive Officer of the Department of Agriculture and Food and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.

Copyright © Western Australian Agriculture Authority, 2014