Influence of multiple- and single-species infestations on herbivore-induced cotton volatiles and Anthonomus grandis behaviour

Abstract

Plants interact with multiple organisms throughout their life cycle. As a result, they are commonly attacked by multiple species of herbivores, leading to the induction of plant defence systems. Herbivore-induced plant volatiles (HIPVs) play an important role in the interaction between community members and can be used to manipulate insect pest behaviour, being a valuable tool in integrated pest management strategy. In this study, the interaction of two chewing insects, the boll weevil, Anthonomus grandis, and the fall armyworm, Spodoptera frugiperda, and of one piercing-sucking insect, the Neotropical brown stinkbug, Euschistus heros, was evaluated for the induction of volatile compounds in cotton under single-and multiple-species attacks. As a control, the emissions of undamaged plants were also measured. In addition, the effect of HIPVs on boll weevil behaviour was also assessed. Qualitatively, single-and multiple-species herbivory induced a similar volatile blend. There was, however, a difference in the amount and proportion of compounds emitted. Plants infested with E. heros emitted a blend of volatiles more similar to that of the undamaged control compared to the other herbivore-induced treatments. The plant volatiles emitted due to simultaneous multiple-species herbivory were induced faster than volatiles emitted by sequential herbivory events, indicating different induction mechanisms depending on the attack configuration. In addition, cotton volatiles induced by an individual attack of A. grandis were attractive to conspecifics, as were the volatiles induced by multiple-species herbivory in both simultaneous and sequential attacks. The use of cotton HIPVs, both under multiple-and single-species attack, can be used for the development of alternative methods for semiochemical-based weevil management, e.g., enrichment of aggregation pheromone traps with plant volatiles. Keywords Boll weevil • Euschistus heros • Semiochemicals • Spodoptera frugiperda • Y-tube olfactometer Key message • Single-and multiple-species herbivory induced qualitatively similar but quantitatively different volatile blends in cotton. The order of herbivores attack is an important feature regulating cotton plants volatile emission. • Anthonomus grandis presents positive chemotaxis to herbivore-induced volatiles when conspecifics are present in the plant in both single-and multiple-species herbivory, thus being able to recognize the presence of conspecifics even when heterospecifics are also present in cotton plants. • Herbivore-induced cotton volatiles can be applied in semiochemical-based A. grandis management.

Olfactometer Responses of Convergent Lady Beetles Hippodamia convergens (Coleoptera: Coccinellidae) to Odor Cues from Aphid-Infested Cotton Plants Treated with Plant-Associated Fungi

“…The air was monitored, checking the flowmeter during the whole observation to ensure it was not escaping and interfering with the assay. After five individuals were tested, we changed the Y-tube, the jars, and the treatment sides to avoid positional bias [52,53]. Jars were cleaned with fragrance-free soap, rinsed with water, and dried in an oven at 80 °C to sterilize and avoid residuals from the previous treatment [50].…”

Improvement of Bemisia tabaci (Hemiptera: Aleyrodidae) Fitness on Chinese Kale upon Simultaneous Herbivory by Plutella xylostella (Lepidoptera: Plutellidae)

“…Damage by herbivores can induce changes in the morphological characteristics and physiological metabolism of host plants [ 4 , 5 ]. The changes in host plants can affect host selection, survival, fecundity, and population dynamics of herbivores, as well as their interactions [ 6 , 7 , 8 ]. Phytochemical defense responses against herbivores are often herbivore-specific and depend to some extent on the feeding mode of herbivores.…”

Differential induction of volatiles in rice plants by two stink bug species influence behaviour of conspecifics and their natural enemy Telenomus podisi

“…When feeding on plants, herbivores (chewing or piercing-sucking species) induce a specific defence response of the plants, which involves the enhanced production of secondary metabolites, comprising both volatile and non-volatile compounds. The plant defence response depends on the ability of the plant to recognize the type of herbivore that is feeding on it, that is, the nature of the feeding habit (chewing or piercing-sucking; De Moraes et al, 1998;Par e & Tumlinson, 1998), as well as the intensity of the injury (Rodriguez-Saona et al, 2010;Magalhães et al, 2018;Michereff et al, 2018). The plant defence response depends on the ability of the plant to recognize the type of herbivore that is feeding on it, that is, the nature of the feeding habit (chewing or piercing-sucking; De Moraes et al, 1998;Par e & Tumlinson, 1998), as well as the intensity of the injury (Rodriguez-Saona et al, 2010;Magalhães et al, 2018;Michereff et al, 2018).…”

“…The volatile compounds, known as herbivoreinduced plant volatiles (HIPVs), are involved in the attraction of parasitoids and predators (Moraes et al, 2005;Michereff et al, 2011;Magalhães et al, 2019). The plant defence response depends on the ability of the plant to recognize the type of herbivore that is feeding on it, that is, the nature of the feeding habit (chewing or piercing-sucking; De Moraes et al, 1998;Par e & Tumlinson, 1998), as well as the intensity of the injury (Rodriguez-Saona et al, 2010;Magalhães et al, 2018;Michereff et al, 2018). Various signals related to herbivores are able to activate the plant defence mechanism.…”