TY - JOUR

T1 - Plant composition, not richness, drives occurrence of specialist herbivores

AU - Knuff, Anna K.

AU - Staab, Michael

AU - Frey, Julian

AU - Helbach, Jan

AU - Klein, Alexandra Maria

N1 - Publisher Copyright: © 2019 The Royal Entomological Society

PY - 2019/12/1

Y1 - 2019/12/1

N2 - 1. How herbivore plant diversity relationships are shaped by the interplay of biotic and abiotic environmental variables is only partly understood. For instance, plant diversity is commonly assumed to determine abundance and richness of associated specialist herbivores. However, this relationship can be altered when environmental variables such as temperature covary with plant diversity. 2. Using gall-inducing arthropods as focal organisms, biotic and abiotic environmental variables were tested for their relevance to specialist herbivores and their relationship to host plants. In particular, the hypothesis that abundance and richness of gall-inducing arthropods increase with plant richness was addressed. Additionally, the study asked whether communities of gall-inducing arthropods match the communities of their host plants. 3. Neither abundance nor species richness of gall-inducing arthropods was correlated with plant richness or any other of the tested environmental variables. Instead, the number of gall species found per plant decreased with plant richness. This indicates that processes of associational resistance may explain the specialised plant herbivore relationship in our study. 4. Community composition of gall-inducing arthropods matched host plant communities. In specialised plant herbivore relationships, the presence of obligate host plant species is a prerequisite for the occurrence of its herbivores. 5. It is concluded that the abiotic environment may only play an indirect role in shaping specialist herbivore communities. Instead, the occurrence of specialist herbivore communities might be best explained by plant species composition. Thus, plant species identity should be considered when aiming to understand the processes that shape diversity patterns of specialist herbivores.

AB - 1. How herbivore plant diversity relationships are shaped by the interplay of biotic and abiotic environmental variables is only partly understood. For instance, plant diversity is commonly assumed to determine abundance and richness of associated specialist herbivores. However, this relationship can be altered when environmental variables such as temperature covary with plant diversity. 2. Using gall-inducing arthropods as focal organisms, biotic and abiotic environmental variables were tested for their relevance to specialist herbivores and their relationship to host plants. In particular, the hypothesis that abundance and richness of gall-inducing arthropods increase with plant richness was addressed. Additionally, the study asked whether communities of gall-inducing arthropods match the communities of their host plants. 3. Neither abundance nor species richness of gall-inducing arthropods was correlated with plant richness or any other of the tested environmental variables. Instead, the number of gall species found per plant decreased with plant richness. This indicates that processes of associational resistance may explain the specialised plant herbivore relationship in our study. 4. Community composition of gall-inducing arthropods matched host plant communities. In specialised plant herbivore relationships, the presence of obligate host plant species is a prerequisite for the occurrence of its herbivores. 5. It is concluded that the abiotic environment may only play an indirect role in shaping specialist herbivore communities. Instead, the occurrence of specialist herbivore communities might be best explained by plant species composition. Thus, plant species identity should be considered when aiming to understand the processes that shape diversity patterns of specialist herbivores.

KW - Associational resistance

KW - biodiversity–ecosystem functioning

KW - herbivory

KW - identity effects

KW - plant galls

KW - plant–insect interactions

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=85067387011&partnerID=8YFLogxK

U2 - 10.1111/een.12767

DO - 10.1111/een.12767

M3 - Journal articles

AN - SCOPUS:85067387011

VL - 44

SP - 833

EP - 843

JO - Ecological Entomology

JF - Ecological Entomology

SN - 0307-6946

IS - 6

ER -