Presseinformation: Drought alters pest infestations

Nr. 101 - 28.07.2026

Researchers show interaction between sugar beet and its pest varies depending on drought stress

Drought creates increasing challenges for agriculture: as well as affecting the growth of crops, it also affects interactions with pests. A research team at the University of Göttingen has investigated how different levels of drought affect the susceptibility of sugar beet to damage caused by the beet leaf miner (Pegomya cunicularia) – a fly whose larvae create visible tunnels inside the leaves. The study shows that moderate drought actually promotes the development of the larvae, whilst severe drought has an adverse effect on both plants and pests. The findings were published in the Journal of Experimental Botany.

The researchers exposed sugar beet plants to either moderate or severe drought. They combined these conditions with an infestation by the beet leaf miner. They then analysed various indicators of plant performance, as well as the development of the insects and their egg-laying behaviour. The outcome depended very much on the severity of the stress: in general, drought reduced the growth of the sugar beet, its leaf area and the rate of photosynthesis. Under moderate drought, however, the concentration of certain nutrients in the leaves increased. This meant the larvae grew particularly well and caused more severe damage to the plant. Under severe drought, however, the plants’ water content and physiological performance decreased significantly, which considerably restricted larval development.

The plant’s chemical communication was also affected: “We observed that drought stress alters both the composition and abundance of plant-emitted volatile compounds, which the beet leaf miner uses to locate suitable host plants for its larvae,” explains Dr Shahinoor Rahman, who carried out the study as part of his PhD research at Göttingen University’s Department for Crop Sciences. “In addition, females laid fewer eggs on plants experiencing severe stress”, Rahman adds. These findings provide new insights into how climate-related changes shape crop–pest interactions and may help inform future strategies for more resilient farming systems.

Original publication: Rahman et al. (2026). Metabolic trade-offs in sugar beet under drought and beet leaf miner infestation: implications for herbivore success. Journal of Experimental Botany. DOI: 10.1093/jxb/erag196

Contact:

Dr Shahinoor Rahman

University of Göttingen

Department for Crop Sciences

Agricultural Entomology Research Group

Grisebachstrasse 6, 37077 Göttingen, Germany

Email: srahman@uni-goettingen.de

www.uni-goettingen.de/en/631071.html

Professor Michael Rostás

University of Göttingen

Department for Crop Sciences

Agricultural Entomology Research Group

Grisebachstrasse 6, 37077 Göttingen, Germany
Email: michael.rostas@uni-goettingen.de