Bioinsecticides to control insect pest populations

Insects are an essential components of many ecosystems (pollinators, pests, etc.). In agricultural and forestry practice, synthetic chemical insecticides are often used to control pests. However, they also pose a health risk to humans and many ecosystems and have a negative impact on beneficial insects and other organisms. In addition, the long-term use of chemical insecticides leads to pest resistance, which gradually reduces their effectiveness. Therefore, there is great interest in replacing chemical insecticides with biological alternatives. The most effective biopesticides include insect pathogens such as nematodes, fungi and bacteria. They are still used to a limited extent and represent a supplement to conventional insecticides. The limited use of biopesticides is due to several factors, such as their slower action, their sensitivity to environmental conditions or their limited market supply. As part of this project, we will expand the possible use of biopesticides by combining them with other pathogens. When infected with pathogens, the host, e.g. a harmful insect, recognizes the foreign organisms and activates the corresponding defence reactions. Influencing these defense reactions is therefore one way of increasing the effectiveness of biopesticides. These biopesticides can be modified by combining them with RNA interference (RNAi), which increases the effect and does not harm non-target organisms. In practice, RNAi can be induced (with double-stranded RNA (dsRNA)) to block genes of the insect immune system and thus enhance the effect of pathogens. By blocking these genes, the pest is weakened or killed. Biopesticides using RNAi can be targeted against specific pests (as they are highly specific) without harming non-target organisms such as pollinators and other beneficial insects. Another focus of the project is to monitor the effects of the biopesticides developed on non-target organisms and to raise awareness of biopesticides. For practical reasons, the project concentrates on selected agricultural and forestry insect pests, the spruce bark beetle, the spongy moth and the Colorado potato beetle. In addition, the complete sequence of their genomes is available, making them suitable for the use of molecular biology methods to modify existing bioinsecticides, which may subsequently have a positive impact on the control of their populations. We will first test the new pesticides on the Colorado potato beetle and then modify them for the spruce bark beetle and the spongy moth.