Plant–animal interactions

• When describing plant–animal interaction networks, sampling can be performed using plant- or animal-centred approaches. Despite known effects of sampling on network structure, how samplings affect the estimates of interaction β-diversity across networks is still unresolved.

• We investigated how the sampling method affects the assessment of β-diversity of interactions, turnover and rewiring. We contrasted plant- and animal-centred sampling methods applied to pollination networks across habitats in a heterogeneous tropical landscape, the Pantanal Wetlands. We also asked whether plant traits influence the difference in interaction specialization according to sampling.

• Plant-centred networks resulted in higher β-diversity of interactions in space than animal-centred networks. Turnover explained most of the β-diversity in both methods, but rewiring was proportionately more important when using the animal-centred method. While the plant-centred method indicated lower network modularity and specialization, floral traits modulated the effects of the sampling method on species-level network metrics.

• Combining animal- and plant-centred approaches returned intermediate values for β-diversity of interactions and network metrics. Distinct methods may also be better suited for answering questions at different scales. Our results point out that the method choice, or combination of methods, should always reflect the appropriate scale of the factors determining the interactions being investigated.

Biography

Camila Souza is currently a collaborating professor and postdoctoral researcher in the Postgraduate Program in Applied Botany at the State University of Montes Claros, Minas Gerais, Brazil. She works with mutualistic interactions, understanding patterns and processes of these interactions mainly in tropical communities. She mainly researches plants and their pollinators and how these interactions can vary in time and space. Currently she is studying multilayer interactions networks to understand temporal layers connections (diurnal and nocturnal interactions and dry and wet seasons) and behavioural layers of floral visitors and their structuring processes.

https://doi.org/10.1111/nph.17334

• The phenotypic plasticity of flowering plants in response to herbivore damage to vegetative tissues can affect plant interactions with flower-feeding organisms. Such induced systemic responses are probably regulated by defence-related phytohormones that signal flowers to alter secondary chemistry that affects resistance to florivores. Current knowledge on the effects of damage to vegetative tissues on plant interactions with florivores and the underlying mechanisms is limited.

• We compared the preference and performance of two florivores on flowering Brassica nigra plants damaged by one of three herbivores feeding from roots or leaves. To investigate the underlying mechanisms, we quantified expression patterns of marker genes for defence-related phytohormonal pathways, and concentrations of phytohormones and glucosinolates in buds and flowers.

• Florivores displayed contrasting preferences for plants damaged by herbivores feeding on roots and leaves. Chewing florivores performed better on plants damaged by folivores, but worse on plants damaged by the root herbivore. Chewing root and foliar herbivory led to specific induced changes in the phytohormone profile of buds and flowers. This resulted in increased glucosinolate concentrations for leaf-damaged plants, and decreased glucosinolate concentrations for root-damaged plants.

• The outcome of herbivore–herbivore interactions spanning from vegetative tissues to floral tissues is unique for the inducing root/leaf herbivore and receiving florivore combination.

Biography

Quint Rusman's research focuses on the importance of biotic interactions for the ecology and evolution of communities. During his PhD, he especially focussed on indirect herbivore – flower-visitor interactions and their contribution to the evolution of plant defence and reproduction. In his current postdoc, he focuses on experimental coevolution between a plant and its pollinating herbivore in environments varying in abiotic and biotic factors. He is also very much interested in insect and plant diversity, and in his free time likes to go hunt for special plants, mostly orchids, and insects, mostly bees.

https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.17931

• Herbivore population dynamics are strongly influenced by the interactions established through their shared host. Such plant-mediated interactions can occur between different herbivore species and different life developmental stages of the same herbivore. However, whether these interactions occur between leaf-feeding herbivores and their soil-dwelling pupae is unknown.

• We studied whether tomato (Solanum lycopersicum) leaf herbivory by the American serpentine leafminer Liriomyza trifolii affects the performance of conspecific pupae exposed to the soil headspace of the plant. To gain mechanistic insights, we performed insect bioassays with the jasmonate-deficient tomato mutant def-1 and its wild-type, along with phytohormones, gene expression and root volatiles analyses.

• Belowground volatiles accelerated leafminer metamorphosis when wild-type plants were attacked aboveground by conspecifics. The opposite pattern was observed for def-1 plants, in which aboveground herbivory slowed metamorphosis. Leafminer attack induced jasmonate and abscisic acid accumulation and modulated volatile production in tomato roots in a def-1-dependent manner.

• Our results demonstrate that aboveground herbivory triggers changes in root defence signalling and expression, which can directly or indirectly via changes in soil or microbial volatiles, alter pupal development time. This finding expands the repertoire of plant–herbivore interactions to herbivory-induced modulation of metamorphosis, with potential consequences for plant and herbivore community dynamics.

Biography

Rocío Escobar-Bravo is a chemical and molecular plant ecologist. She obtained her PhD in 2013 at the Institute for Mediterranean and Subtropical Horticulture "La Mayora" in Málaga, Spain. Between 2014 and 2022, she has worked as a postdoctoral researcher at Prof. Peter Klinkhamer’s lab, at the Institute of Biology of Leiden (The Netherlands), and later at Prof. Matthias Erb’s lab, at the Institute of Plant Sciences of the University of Bern (Switzerland). Her research revolves around how light and volatile cues modulate plant defense responses to herbivorous enemies and how herbivore-induced plant responses affect herbivore performance and survival.

https://doi.org/10.1111/nph.17966