Changes in arthropod community but not plant quality benefit a specialist herbivore on plants under reduced water availability

We found that P. rapae larvae experienced higher survival on R. indica growing under low water availability compared with plants grown under high water availability. Higher survival of eggs and larvae was related to the reduced abundance of other herbivores and natural enemies. Water availability had differential impacts on other members of the herbivore community by altering plant quality.

Low water availability decreased the quality of R. indica to most herbivores, as indicated by reduced abundance in the field and decreased relative growth rate in laboratory feeding assays. In contrast, P. rapae larval performance was not affected by sympatric R. indica grown under different water availability. These results indicate that local P. rapae populations possess physiological adaptations to overcome fluctuations in host quality.

Our findings illustrate that reduced water availability is beneficial to a specialist herbivore but detrimental to most other herbivores. Our work highlights the complex effects of the arthropod communities associated with plants in determining the impacts of water availability on insect herbivores.

Usage notes

This dataset contains the data and codes in the paper titled: Changes in arthropod community but not plant quality benefit a specialist herbivore on plants under reduced water availability. Please refer to the paper in journal Oecologia for details.