EOI to assist with the delivery of More effective control of pest molluscs (snails and slugs) in Australian grain crops

Background

Several exotic snail and slug species of European origin have established in Australian cropping regions and become significant pests of grain crops. Slugs and snails attack seedling crops, resulting in plant damage and yield impacts and losses associated with the costs of resowing and field control. Snails, additionally, climb crop plants in spring and contaminate the grain harvest, creating significant harvest costs (harvester modifications, damage to machinery, post-harvest grain cleaning) and losses (grain value downgrades, receival rejections) for affected growers, and pose serious market access risks for the industry. Mollusc management consists of an integrated, year-round approach comprising cultural, mechanical, and chemical (baiting) methods, including: physical control methods prior to crop sowing (e.g., stubble burning, slashing, rolling, cabling and grazing), chemical control methods prior to crop harvest (e.g., baiting in the field with approved chemicals) and physical control methods at or after harvest (e.g., use of a modified header, grain cleaning).

Research on the impact of snails in the grains industry has occurred since the 1980s, and GRDC has a history of investment in novel approaches to mollusc control, some of which are ongoing.Early work focused on biology and ecology (in permanent pastures, in pasture-cereal rotations, and some limited work in continuous cropping rotations), developing engineering solutions, improving baiting efficacy, and the introduction of a parasitoid fly. Some aspects of the integrated control program (stubble bashing, stubble burning, tillage, grazing, header modifications) developed and adopted during the 1990s and 2000s, have become less practical since the adoption of no-till farming. More recent research has led to new information and more refined guidelines to assist growers to maximise the cost-effectiveness of molluscicidal baiting programs. Collective research efforts have led to the development and adoption of improved integrated control programmes and some very promising approaches for further research. However, even when performed exceptionally well, best practice management does not always reduce mollusc pressures significantly. The development of improved management tactics for snails and slugs remains a priority to improve growers’ profitability and ensure Australia’s market access is maintained.

Respondents are to consider opportunities to develop new knowledge and diverse approaches that can be implemented effectively for monitoring and managing slugs and snails, including improved physical, cultural, chemical, and biological tools and technologies, to minimise losses and maximise market opportunities. Respondents could consider opportunities to:

• Improve knowledge and understanding of mollusc biology and ecology to identify and exploit weaknesses and vulnerabilities in their lifecycles to maximise baiting effectiveness and achieve better management outcomes.
• Explore potential new formulations/actives/delivery systems, including molecules from novel sources, for their potential as molluscides, attractants or repellents, in conjunction with commercial partners where relevant.
• Use knowledge of mollusc movement and behaviour to evaluate physical approaches (e.g., trap crops, barriers, aggregation mechanisms and traps) to exclude and/or concentrate molluscs for targeted management.
• Explore the relative palatability of different crops and varieties to herbivory by pest molluscs to identify opportunity crops/rotations/break crops that could be used strategically to reduce the impact of pest molluscs.
• Quantify the effects of using strategic physical/cultural approaches (incl. burning/cultivation/cabling) in different farming systems and whether sustained, economic benefits can be realised to reduce mollusc pressure.
• Explore opportunities for tools and technologies to detect, identify, quantify and determine special/temporal distribution of molluscs in paddock and at harvest to inform targeted management actions including removal/segregation of snails.
• Investigate best bet options for precision detection and engineering solutions for removal/separation that target snails along the supply chain, in conjunction with key industry and/or commercial partners.

The focus of this EOI is the development of well-timed, integrated management approaches for slugs and snails that deliver multiple benefits to Australian grain growers and advisers by enabling them to minimise control failures, maximise market opportunities and derive sustained benefits that consider the seasonal threats posed by these pests. For the strategies to be readily adopted and implemented successfully, Respondents could consider opportunities to:

• Understand the influence of climate variability and farming systems changes on the pest status of molluscs (seasonal and paddock risk).
• Enable accurate forecasting of mollusc activity to maximise baiting efficacy and increase grower confidence in the proactive implementation of management strategies using understanding of the environmental triggers for mollusc movement and seasonal activity patterns.
• Provide growers and advisers with an understanding of the percentage control targets for snails and slugs to inform the true impacts and economic benefits of baiting and other field control operations.
• Provide growers and advisers with an understanding of the economics and feasibility of different physical/cultural practices that are available in the paddock and at harvest to inform decision making.
• Measure grower practice change to determine levels of adoption and any barriers to best practice management.