Bridging biotremology and chemical ecology: a new terminology.

Living organisms use both chemical and mechanical stimuli to survive in their environment. Substrate-borne vibrations play a significant role in mediating behaviors in animals and inducing physiological responses in plants, leading to the emergence of the discipline of biotremology. Biotremology is experiencing rapid growth both in fundamental research and in applications like pest control, drawing attention from diverse audiences.

Plant protection and biotremology: fundamental and applied aspects.

There is overwhelming evidence that synthetic pesticides have a negative impact on the environment and human health, emphasizing the need for novel and sustainable methods for plant protection. A growing body of literature reports that plants interact through substrate-borne vibrations with arthropod pests and mutualistic arthropods that provide biological control and pollination services. Here, we propose a new theoretical framework that integrates insights from biological control, the ecology of fear, and plant-borne vibrations, to address plant-insect interactions and explore new, sustainable opportunities to improve plant health and productivity.

Plant ecoacoustics: a sensory ecology approach.

Many interactions of plants with the environment have an acoustic component, including the actions of herbivores and pollinators, wind and rain. Although plants have long been tested for their response to single tones or music, their response to naturally occurring sources of sound and vibration is barely explored. We argue that progress in understanding the ecology and evolution of plant acoustic sensing requires testing how plants respond to acoustic features of their natural environments, using methods that precisely measure and reproduce the stimulus experienced by the plant.

Adaptation without Specialization Early in a Host Shift.

AbstractStudents of speciation debate the role of performance trade-offs across different environments early in speciation. We tested for early performance trade-offs with a host shift experiment using a member of the species complex of treehoppers (Hemiptera: Membracidae). In this clade of plant-feeding insects, different species live on different host plants and exhibit strong behavioral and physiological host specialization.

Leaf vibrations produced by chewing provide a consistent acoustic target for plant recognition of herbivores.

Plant defenses that respond to the threat of herbivory require accurate sensing of the presence of herbivores. Herbivory cues include mechanical damage, elicitors from insect saliva or eggs, and airborne volatiles emitted by wounded plants. Plants can also respond to the leaf vibrations produced by chewing herbivores.

Use of Yellow Fluorescent Protein Fluorescence to Track Expression in Responses to Insect Herbivory.

Feeding by chewing insects induces chemical defenses in plants that are regulated by the jasmonic acid (JA) pathway. Jasmonates are usually quantified by liquid chromatography-mass spectrometry (LC-MS) analysis of precursors and products in the biosynthetic pathway or inferred from the extraction and expression of genes known to respond to elevated levels of JA. Both approaches are costly and time consuming.

Caterpillar Chewing Vibrations Cause Changes in Plant Hormones and Volatile Emissions in .

Plant perception of insect feeding involves integration of the multiple signals involved: wounding, oral secretions, and substrate borne feeding vibrations. Although plant responses to wounding and oral secretions have been studied, little is known about how signals from the rapidly transmitted vibrations caused by chewing insect feeding are integrated to produce effects on plant defenses. In this study, we examined whether 24 h of insect feeding vibrations caused changes in levels of phytohormones and volatile organic compounds (VOCs) produced by leaves of when they were subjected to just feeding vibrations or feeding vibrations and wounding + methyl jasmonate (MeJA), compared to their respective controls of silent sham or wounding + MeJA.

Methods for Replicating Leaf Vibrations Induced by Insect Herbivores.

Testing plant responses to natural sources of mechanical vibration requires methods that can precisely reproduce complex vibrational stimuli. Here we describe a method for conducting high-fidelity vibrational playbacks using consumer audio equipment and custom-written signal processing software.

You stay, but I Hop: Host shifting near and far co-dominated the evolution of treehoppers.

The importance and prevalence of phylogenetic tracking between hosts and dependent organisms caused by co-evolution and shifting between closely related host species have been debated for decades. Most studies of phylogenetic tracking among phytophagous insects and their host plants have been limited to insects feeding on a narrow range of host species. However, narrow host ranges can confound phylogenetic tracking (phylogenetic tracking hypothesis) with host shifting between hosts of intermediate relationship (intermediate hypothesis).

Vibration-guided mate searching in treehoppers: directional accuracy and sampling strategies in a complex sensory environment.

Animal movement decisions involve an action-perception cycle in which sensory flow influences motor output. Key aspects of the action-perception cycle involved in movement decisions can be identified by integrating path information with measurement of environmental cues. We studied mate searching in insects for which the primary sensory cues are mechanical vibrations traveling through the tissues of living plants.

Negative feedback from maternal signals reduces false alarms by collectively signalling offspring.

Within animal groups, individuals can learn of a predator's approach by attending to the behaviour of others. This use of social information increases an individual's perceptual range, but can also lead to the propagation of false alarms. Error copying is especially likely in species that signal collectively, because the coordination required for collective displays relies heavily on social information.

The public world of insect vibrational communication.

Food webs involving plants, herbivorous insects and their predators account for 75% of terrestrial biodiversity (Price 2002). Within the abundant arthropod community on plants, myriad ecological and social interactions depend on the perception and production of plant-borne mechanical vibrations (Hill 2008). Study of ecological relationships has shown, for example, that termites monitor the vibrations produced by competing colonies in the same tree trunk (Evans et al.

The importance of female choice, male-male competition, and signal transmission as causes of selection on male mating signals.

Selection on advertisement signals arises from interacting sources including female choice, male-male competition, and the communication channel (i.e., the signaling environment).

Modeling complex phenotypes: generalized linear models using spectrogram predictors of animal communication signals.

A major goal of evolutionary biology is to understand the dynamics of natural selection within populations. The strength and direction of selection can be described by regressing relative fitness measurements on organismal traits of ecological significance. However, many important evolutionary characteristics of organisms are complex, and have correspondingly complex relationships to fitness.

Host shifts and the beginning of signal divergence.

Divergence between populations adapting to different environments may be facilitated when the populations differ in their sexual traits. We tested whether colonizing a novel environment may, through phenotypic plasticity, change sexual traits in a way that could alter the dynamics of sexual selection. This hypothesis has two components: changes in mean phenotypes across environments, and changes in the genetic background of the phenotypes that are produced -- or genotype x environment interaction (G x E).

Evidence that female preferences have shaped male signal evolution in a clade of specialized plant-feeding insects.

Mate choice is considered an important influence in the evolution of mating signals and other sexual traits, and--since divergence in sexual traits causes reproductive isolation--it can be an agent of population divergence. The importance of mate choice in signal evolution can be evaluated by comparing male signal traits with female preference functions, taking into account the shape and strength of preferences. Specifically, when preferences are closed (favouring intermediate values), there should be a correlation between the preferred values and the trait means, and stronger preferences should be associated with greater preference-signal correspondence and lower signal variability.

A method for two-dimensional characterization of animal vibrational signals transmitted along plant stems.

Conventional approaches to measuring animal vibrational signals on plant stems use a single transducer to measure the amplitude of vibrations. Such an approach, however, will often underestimate the amplitude of bending waves traveling along the stem. This occurs because vibration transducers are maximally sensitive along a single axis, which may not correspond to the major axis of stem motion.

The contribution of tympanic transmission to fine temporal signal evaluation in an ultrasonic moth.

In lesser waxmoths Achroia grisella, pair formation and female mate choice involve very fine discrimination of male ultrasonic signals. Female A. grisella prefer male signals with longer pulses and longer ;asynchrony intervals', and evaluate differences in these characteristics in the range of 80-260 mus.

Vibrational communication facilitates cooperative foraging in a phloem-feeding insect.

Insects are the dominant herbivores in tropical forests, with a range of mechanisms for exploiting plant resources. For group-living species, such mechanisms may involve communication. The Neotropical treehopper Calloconophora pinguis (Hemiptera: Membracidae) is a sap-feeding species in which groups of siblings feed on new leaves during the brief period of leaf expansion.

Vibrational communication and reproductive isolation in the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae).

Sexual communication can contribute to population divergence and speciation because of its effect on assortative mating. We examined the role of communication in assortative mating in the Enchenopa binotata species complex of treehoppers. These plant-feeding insects are a well studied case of sympatric speciation resulting from shifts to novel host-plant species.

THE RECONSTRUCTION OF ANCESTRAL CHARACTER STATES.

The problem of error in the phylogenetic reconstruction of ancestral character states is explored by developing the model of Frumhoff and Reeve (1994). Information about the evolutionary rate of change within a character is inferred from the distribution of its character states on a known phylogeny, and this information is used to impose confidence limits on the error associated with ancestral state inference. Ancestral state inference is found to be remarkably robust under the model assumptions for a wide range of parameter values; however, the probability of error increases when the number of species within a clade is small and/or state-transition probabilities are strongly skewed in favor of the non-ancestral state.