With plentiful rain and long summer day lengths, Scotland producing some of the highest yielding and best quality crops in the world. But conditions that promote good crop growth are often good for pests and pathogens too and in Scotland 15-20% of our crops are lost to pests and diseases annually.
These losses to pests and diseases amount to almost a million lost tonnes per year with a value close to £200 million. Dealing with the endemic disease burden inevitably means higher prices in supermarkets, hard times for growers and a knock to the economy but, in addition to this current burden many more pests and pathogens are arriving or threatening our borders. Priority concerns for the sector are sustainable methods of reducing and managing pest and disease risks that lessen reliance on pesticides. Current acute issues which have been highlighted by stakeholders are pesticide resistance developments in some of our endemic pests and diseases, and also concerns over product withdrawals through the regulatory processes. Concerns over resistance development in endemic diseases are a major plant health concern in many crops in the agriculture sector. Potato blight and ramularia in barley being two current example where new issues emerged in 2017.
There are several species of insects that could vector Xylella fastidiosa in the UK including the meadow spittlebug (Philaenus spumarius), which is very common in Scotland. An outbreak of Xylella in Scotland would have serious impacts on the affected grower/nursery and any other host plant-related activities/business within a 5km buffer zone. Therefore, in order to establish the potential for these bacteria to spread, should they be introduced, it is important to identify and get an understanding of the abundance of potential Xylella vectors in Scotland. The WrEN project (http://www.wrenproject.com/), presents a unique opportunity to make use of existing insect collections to map the occurrence of potential Xylella vectors within agricultural woodlands across Scotland. Since 2013, partners on the WrEN project have surveyed over 130 secondary and ancient woodland sites for habitat and wildlife in two regions of mainland Britain. To date, over 1100 species have been recorded from a wide range of taxa. Vegetation structure has been characterised at all sites including information on tree species richness, tree density and size, understorey and canopy cover. In addition, the surrounding landscape has been mapped at a range of spatial scales up to 3 km from each site.
Impact: This project will contribute to Scottish Government’s preparedness measures for the possible
arrival of Xylella fastidiosa by identifying and mapping the distribution of potential vectors of Xylella
The knowledge required to identify different psyllid species is highly specialised but is essential in order to gain a wider understanding of the disease threat that such insects cause. As few in Scotland have this specialisation (including SASA), it is deemed important to up-skill others by running a training course on psyllid identification for entomologists within Scottish organisations to better enable Scotland to deal with possible Lso threats both now and in the future.
This project will contribute to Scottish Government’s ability to control pests / diseases by increased knowledge on the presence and distribution of Liberibacter solonacearum and its host psyllids in Scotland and the potential of these organisms to cause and spread disease.
This report sets out estimates for the crop loss and value to Scottish crop production should the molluscicide metaldehyde be withdrawn. This would leave ferric phosphate as the only available chemical control option. Short term losses are negligible as the substitution of ferric phosphate carries no additional treatment costs and has equivalent efficacy. Longer term there is some risk should resistance arise to this single site mode of action active, and ferric phosphate (although of lower mammalian toxicity to metaldehyde) has some environmental impacts of its own.