Induction of plant responses to oviposition and feeding by herbivorous arthropods: a comparison

Abstract

Plants may respond both to feeding and oviposition by herbivorous insects. While responses of plants to feeding damage by herbivores have been studied intensively during the past decades, only a few, but growing number of studies consider the reactions of plants towards egg deposition by herbivorous insects. Plants showing defensive response to oviposition by herbivores do not 'wait' until being damaged by feeding, but may instead react towards one of the initial steps of herbivore attack, the egg deposition. Direct plant defensive responses to feeding act directly against the feeding stages of the herbivores. However, a plant may also show direct defensive responses to egg deposition by (a) formation of neoplasms, (b) formation of necrotic tissue (= hypersensitive response), and (c) production of oviposition deterrents. All these plant reactions have directly negative effects on the eggs, hatching larvae, or on the ovipositing females. Indirect plant defensive responses to feeding result in the emission of volatiles (= synomones) that attract predators or parasitoids of the feeding stages. A few recent studies have shown that plants are able to emit volatiles also in response to egg deposition and that these volatiles attract egg parasitoids. Studies on the mechanisms of induction of synomones by egg deposition show several parallels to the mechanisms of induction of plant responses by feeding damage. When considering induced plant defence against herbivores from an evolutionary point of view, the question arises whether herbivores evolved the ability to circumvent or even to exploit the plant's defensive responses. The reactions of herbivores to oviposition induced plant responses are compared with their reactions to feeding induced plant responses.

Does egg deposition by herbivorous pine sawflies affect transcription of sesquiterpene synthases in pine?

“…In several plant species, oviposition-induced volatiles (among them mono- and sesquiterpenes) were shown to attract egg parasitoids (Hilker et al 2002a; Hilker and Meiners 2002; Colazza et al 2004; Mumm and Hilker 2006). These compounds are released locally from the site of egg deposition and also systemically from adjacent egg-free plant parts (e.g., Hilker and Meiners 2006; Hilker et al 2002b).…”

Jasmonic Acid-Induced Changes in Brassica oleracea Affect Oviposition Preference of Two Specialist Herbivores

“…JA treatment of plants results in emission of synomones that attract natural enemies like predatory mites and parasitoids (Dicke et al, 1999; Hilker and Meiners, 2002; Van Poecke and Dicke, 2002; Hilker and Meiners, 2006). This attraction results in a higher natural enemy density around damaged plants, and therefore, it is advantageous for the herbivores to avoid oviposition on induced plants.…”

Foraging behaviour of an egg parasitoid exploiting plant volatiles induced by pentatomids: the role of adaxial and abaxial leaf surfaces

“…Plants can also sense insect oviposition (Hilker & Meiners, 2006; Hilker & Meiners, 2010; Hilker & Fatouros, 2015; Hilker & Fatouros, 2016). For several systems, it is well known that insect oviposition induces the emission of plant synomones that attract specific egg parasitoids (Meiners & Hilker, 1997; Meiners & Hilker, 2000; Hilker & Meiners, 2002; Hilker, Rohfritsch & Meiners, 2002; Colazza et al, 2004; Colazza, McElfresh & Millar, 2004; Fatouros et al, 2005; Fatouros et al, 2007; Fatouros et al, 2008; Fatouros et al, 2009). Generally, the oviposition-induced synomones are perceived by the parasitoids as olfactory stimuli.…”