CRC for Plant Biosecurity - stored grain

Strong resistance to phosphine in the rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae): its characterisation, a rapid assay for diagnosis and its distribution in Australia

CRICHTONA — Mon, 23 Jul 2012 04:41:44 +0000

Strong resistance to phosphine in the rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae): its characterisation, a rapid assay for diagnosis and its distribution in Australia

Review and gap analysis of stored grain sampling strategies

CRICHTONA — Tue, 31 Jan 2012 22:06:25 +0000

Review and gap analysis of stored grain sampling strategies

Case Study 1 - Comparison of Statistical Sampling Models for the Detection of Pests in Stored Grain

CRICHTONA — Tue, 31 Jan 2012 05:47:42 +0000

Case Study 1 - Comparison of Statistical Sampling Models for the Detection of Pests in Stored Grain

CRC50151: Resistance Monitoring (Phase 2)

CRICHTONA — Fri, 20 Jan 2012 00:17:05 +0000

Program

Post-Harvest Integrity

Phosphine still a killer in cooled grain

CRICHTONA — Thu, 30 Jun 2011 00:30:29 +0000

Warm winter days can provide highly fertile conditions for insect pests, especially in southern Queensland and northern New South Wales where toasty temperatures provide an ideal breeding ground for stored grain pests.

With more growers storing grain on-farm to take advantage of a deregulated grain market, stored grain insects have become a greater problem in recent years. Increased on-farm storage is contributing to, and suffering from, growing insect resistance to the industry’s main fumigant, phosphine.

Most grain in Australia is harvested in the warmer months in conditions that can lead to heat-damaged grain and mould; conditions that are favourable to insect pests. To combat this many growers aerate stored grain, to reduce grain temperatures to 20°C or less.

Although lower temperatures maintain grain quality and reduce insect population growth, industry researchers have questioned whether phosphine is as effective at actually killing insects in grain stored at a cooler temperature.

Now, Queensland Department of Employment, Economic Development and Innovation entomologist Dr Greg Daglish and research development agronomist Philip Burrill have determined that phosphine can still be effective at lower temperatures, within certain parameters.

Over a number of years and using both laboratory trials and trials with on-farm silos, they found that phosphine is generally less effective at lower temperatures; but in the right conditions, that is, in a properly sealed, gas-tight silo and with adequate exposure periods, phosphine fumigation of cool grain to control resistant insect populations is possible.

“The benefits of cooling and phosphine fumigation are that cooling preserves grain quality and reduces insect population growth, and phosphine kills insects and has a residue-free status in all major markets,” Dr Daglish says. “The work has proved that cool grain fumigation is an option for growers and meets market needs.”

However, changing temperatures do affect some phosphine-resistant strains of key pests. Dr Daglish says that although the most resistant Australian strains of two pests are known to respond similarly to phosphine, the project showed that one species became much harder to control in cool grain.

It is an important finding for an industry reliant on phosphine to treat stored grain for pests, and where these pests are becoming more resistant to it.

Mr Burrill says the majority of tools growers had for dealing with grain pests 10 to 15 years ago are falling over. “The only thing we can say to growers is that having a well-constructed, aerated and sealable silo gives you the option to fumigate with phosphine, which when done correctly is still effective against all our pests.”

The ‘cool grains’ work, which started as a Grains Research and Development Corporation project, has also highlighted some vital information about phosphine and its interaction with stored sorghum.

For example, an early finding relates to sorghum’s sorption rate (how quickly it absorbs phosphine), which influences fumigation performance. Generally sorghum is more sorptive than wheat.

“It means that when it comes to phosphine fumigation in sorghum, there is less margin for error than for, say, stored wheat, so fumigations need to be spot on,” Dr Daglish says.

Sorption is the major cause of phosphine loss in well-sealed silos. However, in cooled wheat or sorghum, the sorption rate is lower at lower temperatures, meaning that higher concentrations will be achieved for longer.

Another discovery, that older grain tends to be less sorptive, means that delaying fumigation could also help keep phosphine concentrations higher for longer.

Although results for silo trials varied, three general observations were made about phosphine concentrations: lower concentrations tended to be measured deeper in the grain mass; lower concentrations tended to be measured on silos’ northern sides; and concentrations measured higher in the grain mass tended to peak earlier.

Dr Daglish says aluminium phosphide tablets must not be mixed with the grain itself, so tablets are often placed on trays in the silo headspace. When phosphine gas is liberated from one point it takes time to diffuse throughout the whole grain bulk, so gas concentrations are not always distributed uniformly in all parts of the storage.

“It is essential that sufficient time is allowed to ensure maximum gas distribution, to achieve the best results from phosphine fumigation,” he says.

CRC50092: Alternatives to phosphine review

CRICHTONA — Tue, 15 Feb 2011 03:52:15 +0000

Program

Post-Harvest Integrity

10th International Working Conference on Stored Product Protection

VANMEURSA — Tue, 30 Nov 2010 05:17:06 +0000

Dr YongLin Ren travelled to Lisbon, Portugal to attend the 10th International Working Conference on Stored Product Protection (IWCSPP) from 25 July to 3 August. This is the international research conference held every four years and reports advances in this field of research. It is fully focused on stored product insect/pathogen control, monitoring, diagnostic, resistance and quarantine treatment. More than 400 participants were present at the conference.

Dr Ren’s paper has been published in the conference proceedings and he gave two oral presentations at the conference:

Evaluation of headspace Solid Phase Micro-extraction method for analysis of phosphine residues in wheat (full paper and oral presentations)
Are the volatile chemicals from wheat and grain insects (Tribolium castaneum (Herbst), Rhyzopertha dominica (F.) and Sitophilus granarius (L.)) related with inter-communication between insects and host? (oral presentations)

Attending the conference allowed Dr Ren to maintain and establish new contact with various scientists from high profile research establishments that are conducting work in similar fields. It was useful to share innovative results, such as collaboration with China to evaluate and develop semi-nano dust for stored product insect control in unsealed farm bin and shipping containers. Dr Ren also discussed with delegates from the United States and China to establish an international collaborative relationship on the eradication of Khapra beetle and the use of Nitrogen and CA+heat or fumigant for fumigation/sterilization/disinfection of grains and oil seeds. Furthermore, he discussed the possibility of exchangeing students and sharinge curriculum related to the biosecurity of stored grain with Chinese University and Kansas State University delegates.

During the conclusion of conference, the Food and Agriculture Organization raised issues regarding post harvest losses and food and trade security. Dr Ren believed it was very clear at this conference that the IWCSPP has no research strategy on the management of phosphine resistance. However, the 2014 phosphine review is challenging all the grain industry. Very few papers reported using sulphuryl fluoride (SF) for stored grain. It’s main use was reported for flour and structural fumigation.

10th International Working Conference on Stored Product Protection

VANMEURSA — Fri, 26 Nov 2010 04:06:24 +0000

Dr Greg Daglish participated in the 10th International Working Conference on Stored Product Protection (IWCSPP) which was held from 27 June to 2 July 2010 in Estoril, Portugal. The conference gave Dr Daglish the opportunity to:

learn about the recent advances in stored product protection, especially pest ecology and phosphine resistance
develop and strengthen contacts with international experts that will benefit Australian biosecurity and the CRCNPB, and
present research findings from CRC50089: Grain Insect Ecology to international peers.

IWCSPP is the principal meeting for researchers and other professionals interested in stored product protection, particularly protecting grain after harvest, and in 2010 the meeting attracted several hundred delegates from more than 30 countries. There were 201 oral or poster presentations and five specialist workshops on topics including pest biology, engineering, fumigation and controlled atmospheres, and chemical and non-chemical control. Dr Daglish presented a paper entitled Resistance management and the ecology of Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst) in subtropical Australia which provided an overview of the CRCNPB research into two of the most common causes of grain being rejected by the nil tolerance standard in Australia. Dr Daglish also attended presentations and joined workshops on insect sampling and rearing, and talked with as many scientists as possible, especially those involved in his area of interest, ecology detection and control of stored grain pests in North America and Europe.

A sampling workshop was informative, as were a number of oral and poster presentations. There was lively discussion about whether the movement of insects through grain bulks was essentially the processes in which insects act like passive entities. There were strong arguments from both sides, each producing convincing data or arguments. Dr Daglish drew the conclusion that both were likely to be correct depending on the stage of colonization of grain bulks. Another theme in the workshop was the need to use sampling and analysis of sampling data to evaluate and predict the performance chemical control options. These research areas are relevant to Australia.

In CRC50089: Grain Insect Ecology pheromone traps were used to trap beetles in the rural landscape, and Dr Daglish was keen to learn about any new research that might be relevant to Australia.

Internationally, there is considerable interest in the use of pheromones for monitoring and mating disruption, although the latter relates more to insects inside warehouse and other buildings. United States (US) researchers have conducted preliminary research on mating disruption in the lesser grain borer, Rhyzopertha dominica, which is also a major pest in Australia. If successful, mating disruption could be incorporated into an integrated pest management approach, and monitoring their progress will be a priority for Dr Daglish.

CRCNPB research is aiming to determine the levels of movement of the two key pests R. dominica and the rust red flour beetles, Tribolium castaneum, in the Australian rural environment. Australian trapping suggests considerable movement in both species and population genetics so far completed support this view. Canadian and US scientists have strong evidence of an annual spring migration of R. dominica from the US to Canada, and so a spring migration in Australia may be worth investigating. US scientists are trapping R. dominica in native vegetation sites farm from farms and grain silos, which is consistent with our Australian results. Population genetics suggests considerable gene flow between populations of T. castaneum taken from mills across the US. This is consistent with results from CRC50089: Grain Insect Ecology suggesting considerable gene-flow within the Queensland study area. There are clear benefits in keeping in contact with the North American scientists.

It was evident from the conference that there are few new potential fumigants or insecticides for use for stored grain, with sulfuryl fluoride being the notable exception. The adoption of this fumigant has been in the context of fumigating buildings and laboratory and field research on its potential use on grain bulks is urgently needed. Another exception was a fungal-based biopesticide for treating structures being developed in the United Kingdom consortium which may have potential in Australia if the new delivery technology works in practice.

Dr Daglish made the most of networking opportunities especially with stored grain researchers from the United States Department of Agriculture and Kansas State University. Topics of shared interest included grain insect ecology, interpreting trap data and grain protectants.

The next IWCSPP will be held in Thailand in 2014.

Post-harvest pests in the laboratory

VANMEURSA — Thu, 17 Dec 2009 23:03:47 +0000

Complementing the June appointment of Dr Yong Lin Ren as Associate Professor of Stored Grain Research, a new laboratory focused on post-harvest biosecurity was officially opened at Murdoch University on 27 November 2009.

Established at the University’s School of Biological Sciences and Biotechnology, the new laboratory is the nation’s first research and development facility dedicated to improving the quality of stored grain.

The laboratory team and infrastructure are a joint investment of the Cooperative Research Centre for National Plant Biosecurity, Department of Agriculture and Food (WA) and Murdoch University.

The laboratory is strongly supported by CRC grain industry participants – ABB Grain Ltd, Co-operative Bulk Handling Limited, GrainCorp Operations Ltd and the Grains Research and Development Corporation – all who have a vested interest in maintaining trade and market access for Australia’s grain exports.

Principal Scientist, Associate Professor YongLin Ren, said this exciting initiative was timely as post-harvest biosecurity and security of stored grain becomes increasingly important around the world due to the threat of global food shortages.

“The Post-Harvest Biosecurity Stored Grain Research Laboratory will develop new risk mitigation options that will contribute profitably to plant biosecurity, food and trade safety and help maintain the Australian grain industry position as a market leader in domestic and international trade with sound, cost-effective and safe storage technology,” Dr Ren said.

Scientists at the laboratory will undertake biological studies of insect pests and microorganisms that affect stored products, develop pest management strategies and examine stored product management.

The initiative will also increase education and social awareness, providing online information about Australian grain storage, insect management and industry regulations and enhance students’ learning and research in plant biosecurity and food security.

Earlier this year, Dr Yong Lin Ren was appointed as Principal Scientist at Western Australia’s Department of Agriculture and Food to provide leadership and management for its stored grain research team.

To build national capacity in plant biosecurity scientific research, the CRC initiated a project which would allow Dr Ren spend the first three years of his appointment building future capacity as Associate Professor of Stored Grain at Murdoch University.

Photo caption: Murdoch University's Professor Giles Hardy and Dr YongLin Ren hold jars of weevils in the new laboratory.

CRC70085: Personal Digital Assistants (phase two)

VANMEURSA — Tue, 14 Jul 2009 02:01:24 +0000

Program

Delivery and Adoption

This project will allow the rapid and efficient use of all surveillance data to maintain and protect the Australian grains market and potentially other agricultural/horticultural industries.