Volatile organic compounds released by wheat as a result of striped shieldbug feeding and insect behaviour

Abstract

The most popular plant protection method is chemical; however, this is often connected with repeated treatments. Therefore, eco‐friendly strategies need to be investigated. A good alternative is to use the natural repellent properties of plants. The aims of this study were to determine how adult striped shieldbugs (Aelia acuminata L.) feeding on spring wheat plants affect the emission of volatile organic compounds (VOCs) and to determine the reaction of these insects to synthetic blends of VOCs. Using GC/MS for VOC analysis, we find that Aelia acuminata L. (1 or 2 adult pairs) significantly induced VOC emissions from wheat plants. In comparison with controls, larger amounts of (Z)‐3‐hexenal, (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (E)‐2‐hexen‐1‐ol, β‐pinene, β‐myrcene, (Z)‐3‐hexen‐1‐yl acetate, 1‐hexyl acetate, 4‐heptanone, (Z)‐ocimene, linalool, linalool oxide, benzyl acetate, methyl salicylate, indole, β‐caryophyllene and (E)‐β‐farnesene were released as a result of the biotic stress, with two pairs of insects causing a significantly stronger plant reaction. On the basis of the VOCs identified and their emitted concentrations for two pairs of feeding adult striped shieldbugs, two blends of VOCs were prepared in three concentrations: blend I—(Z)‐3‐hexenal, (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (E)‐2‐hexen‐1‐ol, (Z)‐3‐hexen‐1‐yl acetate and 1‐hexyl acetate, and blend II—(Z)‐ocimene, linalool, benzyl acetate, methyl salicylate, β‐caryophyllene and (E)‐β‐farnesene. Using an olfactometer (Y‐tube) to study insect behaviour, it was found that the male striped shieldbugs were not attracted to any of the blends at any concentration. Female shieldbugs were attracted to blend I at concentration 1. As for the remaining concentrations of both blends, females and males were repelled, with the higher the concentration the stronger the insect reaction.

Exogenous Calcium Suppresses the Oviposition Choices of Frankliniella occidentalis (Thysanoptera: Thripidae) and Promotes the Attraction of Orius similis (Hemiptera: Anthocoridae) by Altering Volatile Blend Emissions in Kidney Bean Plants

“…In our study, calcium treatment led to changes in the content of several compounds, among them, the percentages of (E)-2-hexen-1-ol and 1-octen-3-ol were significantly decreased, while the percentages of β-lonone and (E,E)-2,4-hexadienal were significantly increased. In other studies, (E)-2-hexen-1-ol and 1-octen-3-ol have been identified as pest HIPVs, and their increased emissions attract natural enemies of herbivores [69,70]. This finding was contradictory to that of the present study.…”

Relationships between Volatile Organic Compounds Released by Wheat Plants Following Artificial Stress and Their Potential Influence on Natural Pest Management

“…This result may be a confirmation of Pare and Tumlinson's [20] suggestion that the conversion of C 6 compounds into an acetate form is promoted while crossing the undamaged plant tissue barrier. Moreover, using GC/MS, Sendel et al [21] found that Aelia acuminata L. (1 or 2 adult pairs) significantly induced VOC emissions from wheat plants, where, as a result of biotic stress, larger amounts of the following VOCs were released: (Z)-3-hexenal, (E)-2-hexenal, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, β-pinene, β-myrcene, (Z)-3-hexen-1-yl acetate, 1-hexyl acetate, 4-heptanone, (Z)-ocimene, linalool, linalool oxide, benzyl acetate, methyl salicylate, indole, β-caryophyllene, and (E)-β-farnesene. It was also reported by them that two pairs of insects caused a significantly stronger plant reaction.…”

The Role of Ascorbate–Glutathione System and Volatiles Emitted by Insect-Damaged Lettuce Roots as Navigation Signals for Insect and Slug Parasitic Nematodes

“…Plants have developed various defense mechanisms to protect themselves from herbivores. When attacked by insects, many plant species release root exudates, which are mostly volatile compounds (VOCs) that affect the movement of their natural enemies [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Root-exudate-mediated chemotaxis plays a critical role in the multitrophic system of plants, herbivores, and their natural enemies.…”

“…These exudates function as semiochemicals, which directly influence both herbivores and their natural enemies. Some of these compounds are produced in both damaged and undamaged plants [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Different compounds are released when the plant is mechanically injured or when a particular herbivore species feeds on it [ 2 , 4 ].…”