Oviposition by a moth suppresses constitutive and herbivore-induced plant volatiles in maize

Abstract

Plant volatiles function as important signals for herbivores, parasitoids, predators, and neighboring plants. Herbivore attack can dramatically increase plant volatile emissions in many species. However, plants do not only react to herbivore-inflicted damage, but also already start adjusting their metabolism upon egg deposition by insects. Several studies have found evidence that egg deposition itself can induce the release of volatiles, but little is known about the effects of oviposition on the volatiles released in response to subsequent herbivory. To study this we measured the effect of oviposition by Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) moths on constitutive and herbivore-induced volatiles in maize (Zea mays L.). Results demonstrate that egg deposition reduces the constitutive emission of volatiles and suppresses the typical burst of inducible volatiles following mechanical damage and application of caterpillar regurgitant, a treatment that mimics herbivory. We discuss the possible mechanisms responsible for reducing the plant's signaling capacity triggered by S. frugiperda oviposition and how suppression of volatile organic compounds can influence the interaction between the plant, the herbivore, and other organisms in its environment. Future studies should consider oviposition as a potential modulator of plant responses to insect herbivores.

Strong oviposition preference for Bt over non-Bt maize in Spodoptera frugiperda and its implications for the evolution of resistance

“…Oviposition by S. frugiperda affects the production of plant volatiles in maize [22]. Moreover, ovipositing females show a preference for the volatiles of undamaged maize plants [23].…”

Oviposition induced volatiles in tomato plants

“…Oviposition by herbivorous insects can induce indirect plant defence responses whereby volatiles are emitted that attract egg parasitoids (Hilker and Meiners, 2006), although suppression can also occur (Peñaflor et al, 2011). HIPVs provide parasitoids with early alert cues for plants colonised by their host and thus enhance their foraging efficacy (Bruce et al, 2010;Colazza et al, 2004;Hilker and Meiners, 2006).…”

Compostos orgânicos voláteis na defesa induzida das plantas contra insetos herbívoros

“…22,57 A oviposição de Spodoptera frugiperda Smith, 1797 (Lepidoptera: Noctuidae) suprime a emissão de compostos voláteis emitidos por milho. 58 Embora em milho não se tenha avaliado as respostas de outros herbívoros à oviposição de S. frugiperda, em Brachiaria brizantha, a oviposição de Chilo partellus Swinhoe, 1885 (Lepidoptera: Cambridae) reduz a colonização do herbívoro. 59 Segundo Bernasconi e colaboradores, 54 os voláteis induzidos poderiam alertar outros herbívoros sobre a produção de compostos tóxicos pela planta, sobre a presença potencial de competidores, assim como de inimigos naturais que são atraídos após a indução.…”

“…Alguns grupos de pesquisa brasileiros já iniciaram estudos baseados em sistemas que incluem as culturas de soja 86 , milho 58 e tomate. 135 Em nosso laboratorio, pesquisas nesse campo têm sido iniciadas com espécies arbóreas de importância florestal, como o eucalipto (Eucalyptus benthamii Maiden & Cambage).…”