Initial situation/scientific issue

Currently, there is a lack of effective measures to reduce the damage caused by the beet weevil (Asproparthenis punctiventris) in heavily infested sugar beet fields to an economically viable level. Various integrated pest control measures are already in use to regulate the beet weevil. These include drop grooves to prevent the beetles from entering the fields, and aggregation pheromones (Csalomon®, Hungary; AGRANA Eklektor®, Austria) to intercept them. The effectiveness of other biological control methods against the beet weevil has been investigated as part of research projects. For example, in the 'CURCUCONT' project, the use of insect-pathogenic fungi, particularly the Metarhizium brunneum BIPESCO 5 isolate, was investigated as a biological control measure against the beet weevil. This strain of fungus was also tested in combination with drop grooves, but only around 6% of the beetles were infected. Insect-pathogenic fungi thrive primarily in moist soil conditions, whereas the beet weevil itself prefers dry soils. New solutions are needed to sustainably improve the regulation of economically relevant pests.

Project description/methodology

Plant protection measures that are highly selective towards target organisms are becoming increasingly important. RNA interference (RNAi) is a promising approach that offers an alternative to the modes of action of conventional plant protection products. RNAi is a natural cellular defence mechanism that protects against viral infections by blocking the translation of viral messenger RNA (mRNA). This halts the production of viral proteins and, consequently, virus replication. This natural process can also be used to control pests. Specifically designed double-stranded RNA (dsRNA) inhibits the production of a vital proteins in the pest. This mode of action is highly specific because the dsRNA only acts on the mRNA of the target organism with a matching sequence.
The ‘ASPiRNA’ project aims to develop a RNAi-based approach to protect sugar beet plants from beet weevils, investigating its effects on non-target organisms through bioinformatic analyses and injection and feeding trials. The project will contribute to the sustainable management of the beet weevil and the preservation of sugar beet production in Austria.

Outcomes