The potential for modifying plant volatile composition to enhance resistance to arthropod pests.

Abstract

Plant volatiles provide herbivorous arthropods with information that allows them to discriminate between host and non-host plants. Volatiles may also indicate plant stress status, and natural enemies can use herbivore-induced plant volatiles as cues for prey location. Neighbouring plants may also make use of volatile cues to prepare for herbivore attack. Since both constitutive and inducible plant volatile emissions can be modified by plant breeding, the possibility exists to improve plant resistance against important pests both directly and indirectly via improved biological control. So far this approach has been tested only in the realm of research, predominantly using transgenic Arabidopsis with modified composition of terpenoids or C6 green leaf compounds. However, several studies have shown that it is indeed possible both to reduce herbivory and to enhance natural enemy attraction simultaneously. If such effects can be translated into increased and more stable yields in important crops, this strategy might be explored by the plant breeding industry and eventually become available to plant growers in the form of resistant cultivars. There are, however, ecological challenges associated with this approach, and the modified plant volatile composition should preferably be inducible specifically by the target pests, or by field application of specific elicitors based on forecasts of pest attack.

Over what distance are plant volatiles bioactive? Estimating the spatial dimensions of attraction in an arthropod assemblage

“…Volatile compounds released by plants are used by arthropods as foraging cues in the field, and certain compounds, released only in response to herbivore feeding, are especially attractive to parasitic and predatory natural enemies (Vet & Dicke, 1992;Thaler, 1999;Mumm & Dicke, 2010). These herbivore-induced plant volatiles (HIPVs) have subsequently been deployed in agricultural systems with the intent of increasing natural enemy abundance and enhancing pest suppression (Dicke et al, 1990;Turlings & Ton, 2006;Khan et al, 2008;Ahman et al, 2010;Kaplan, 2012). For example, Degenhardt et al (2009) genetically transformed corn to constitutively emit the sesquiterpene (E)-b-caryophyllene, thereby increasing suppression of rootworm larvae by entomopathogenic nematodes.…”

Volatile Semiochemical Mediated Plant Defense in Cereals: A Novel Strategy for Crop Protection

“…Plant volatile mediated direct and indirect defense can be considered as an integral part of plant resistance as it enables recruitment of natural enemies (parasitoids and predators) that parasitizes and kill attacking insect pests and deter infestation by the herbivores [28,33]. Here, we discuss applications of plant-derived volatile semiochemicals in fighting cereal insect pests using Aboveground and belowground herbivore-induced plant volatiles (HIPVs) emitted by maize plant in response to spotted stemborer Chilo partellus oviposition (a) and feeding (b) and the corn rootworm (Diabrotica virgifera virgifera) feeding (d).…”

Phenotypic plasticity in host plant preference of the willow leaf beetlePhratora vulgatissima: the impact of experience made by adults

“…Wrong assumptions about behavioural, physiological or morphological features of the insect population in focus can have costly consequences for the application of biocontrol strategies (Diehl & Bush, ). Thus, the success of biocontrol approaches that are based on the manipulation of pest insect behaviour by plant volatiles depends on the degree of behavioural plasticity of the targeted insect species (Jallow et al ., ; Åhman et al ., ). The less variable the host plant preferences of herbivorous insects, the more effective and robust is the implementation of measures for integrated pest management.…”