Institut für ökologische Chemie, Pflanzenanalytik und Vorratsschutz
BackgroundDuring cultivation and after harvesting (during storage and processing), storable plant products such as cereals and legumes—key components of human and animal nutrition—must be effectively protected against losses. In particular, insect infestation, threaten the quantity and quality of stocks. Worldwide, post-harvest losses of grain are estimated at 5–10%; in tropical regions, they can even reach 30–40% due to insect infestation. The protection of stored goods is therefore a key component of food security.Climate change is exacerbating this problem. Rising temperatures and more frequent extreme weather events increase the risk of uncertain harvests and at the same time increase pest pressure during storage and cultivation. Heat-loving and invasive species could expand their range northward and develop additional generations per year. In addition, milder conditions favor the establishment of outdoor populations, which means that crops can be infested even before storage – a route of entry into storage facilities that has been largely overlooked in temperate latitudes to date. Against the backdrop of climate-related yield fluctuations, optimized storage is becoming increasingly important. The aim is to secure both the available quantity and the hygienic and nutritional quality of staple foods in the long term. However, conventional control measures using chemical pesticides are increasingly viewed critically by society and politicians due to the development of resistance, regulatory restrictions, and environmental concerns. Therefore, the development of sustainable, integrated strategies for the protection of stored dry agricultural products is crucial to ensure both quality preservation and food security.In Germany and other Central European countries, stored product insects have not been considered relevant field pests to date. Since their occurrence was mainly limited to grain storage facilities, they received only limited attention in monitoring programs despite legal requirements (§59 Plant Protection Act). Accordingly, there is a lack of reliable data on their occurrence, distribution, and specific grain losses due to pest infestation. These data gaps make it difficult to develop effective management and early warning strategies. For this reason, in the interests of integrated plant/stored product protection, the focus in future should be more on effective early detection – in addition to optimized storage technology and environmentally friendly control measures. Early monitoring in the field during grain cultivation makes it possible to detect infestation in good time and take targeted countermeasures before storage pests spread and endanger stored products. Preventive strategies are therefore necessary along the entire value chain to minimize the entry of insect pests into grain storage facilities. Modified trap systems and optimized attractant combinations offer promising approaches for this. Early, selective measures can reduce post-harvest losses, decrease the use of chemical pesticides, and thus strengthen food security and environmental protection in the long term.The AVoiD (Defense against Storage Pests in Germany) project, funded by the Federal Ministry of Agriculture, Food, and Regional Identy (BMLEH), laid the foundation for this approach in its “Early Detection” subproject. To this end, a three-year nationwide monitoring program of stored product insects in grain stores and adjacent fields was carried out. Various trap systems with attractants (including pheromones) were tested on conventional and organic farms in six federal states. The results showed a high species diversity (11 moth and 25 beetle species). In addition to findings in storage facilities, several typical storage pests – in particular the lesser grain borer (R. dominica) – occurred in large numbers in the field at almost all locations. Granary weevils (Sitophilus granarius) and sawtoothed grain beetles (Oryzaephilus surinamensis) were also found in large numbers locally in the field. Their occurrence increased significantly, particularly in 2024 and 2025. These findings indicate that some storage pests can already establish themselves outside of storage facilities under Central European climatic conditions. However, as only descriptive data analysis has been carried out so far, there is a lack of reliable analyses of correlations with environmental factors – a keyng point for further research and practical recommendations.SpreadPest investigates the occurrence, distribution and environmental dependence of stored product insects along the grain value chain in Germany. The focus is on two central questions:1. Which species—newly emerging or established—occur in grain-producing, grain-storing, and grain-processing businesses, both indoors and outdoors, and with what frequency and species composition?2. Which climatic, geographical, and farm-specific factors (e.g., temperature, humidity, storage structure, hygiene, management, type of farming) influence the occurrence, hatching, and flight behavior of the pests?The monitoring methodology established in the predecessor project “AVoiD” will be continued and further developed on an adapted scale. At four to five representative locations in Germany, commercial funnel and ground traps will be equipped with species-specific pheromones and used both inside storage facilities and at the edge of fields. The traps will be checked monthly, pheromones changed regularly, and the catches morphologically identified and quantified. Standardized placement ensures comparability with previous data sets. The species composition will be analyzed using multivariate statistical methods. Farm-specific characteristics (e.g., storage structure, stored crops, hygiene measures, type of management) will be recorded annually using standardized questionnaires and integrated into the evaluation as covariates. In addition, temperature and humidity data will be continuously collected via data loggers and climate data from the German Weather Service are included. GIS analyses will also take into account the geographical location, land use, and phenological parameters of the sites.The combination of data from this project and AVoiD will result in an sufficiently long observation period that allows for the analysis of seasonal dynamics and climate-related trends. Generalized linear mixed models (GLMM) will be used to identify key factors influencing pest occurrence and flight activity.
Federal Ministry of Agriculture, Food and Regional Identity
