Tomato: Further optimisation of Macrolophus release and feeding strategies

• Macrolophus pygmaeus adults and nymphs are voracious predators and will feed on whiteflies, Liriomyza leafminers, spider mites and Tuta absoluta. They have the potential to become one of the most useful biological control agents available to tomato growers. However, at £70 - £80 per 1,000, M. pygmaeus is also one of the most expensive, so the predator must always be used as efficiently as possible.
• HDC project PC 302d demonstrated that when M. pygmaeus does establish efficiently it can form the basis of a highly effective IPM control programme for Tuta absoluta. However, establishment and population growth have been inconsistent.
• HDC project PE 020 demonstrated that early season population growth was improved when the predator was provided with supplementary food in the form of Artemia eggs. However, the study also raised questions about the type and condition of that food as well as natural mortality of the purchased M. pygmaeus.
• The results were presented to the Tomato Growers’ Association Technical Committee who requested the continuation of studies during the 2015 growing season (Minutes of TGA TC meeting on 5 September 2014). The TGA TC has since confirmed their support of this Full Proposal for HDC funding (Dr Morley, TGA TC, Pers. Com. 27 September 2014).
• In laboratory-based experiments, the team will compare the suitability of three types of supplementary food with each type tested in dehydrated (i.e. as supplied) and fully hydrated condition.
• If as suspected, the food must be in the fully hydrated state, then a suitable delivery system will be developed for use in tomato crops.
• The most effective type / condition / delivery system of food will then be taken forward to a crop-scale trial. The speed of M. pygmaeus population growth will be measured from four combinations of release rate and feeding strategies. The trials work will be done in commercial crops following the general experimental approach that was successfully developed in HDC project PC 240 and more recently used in HDC projects PC 251, PC 295, PC 302/b/d and PE 020. Experimental design and analysis of data will be done under the guidance of a senior statistician with considerable experience of completing trials under the constraints imposed by commercial crop production.
• WSG has assembled a team of appropriately qualified and experienced personnel to undertake this project. The team have an excellent record of delivering practical solutions and effectively conveying new information to the tomato industry.
• Based on the losses reported within this proposal, the project could provide payback in less than one year.