Essential Oil Compounds for Thrips Control – a Review

Abstract

This review covers aspects of putting essential oil compounds to use either as allelochemicals that manipulate the host selection process of Thysanopteran pest species or as botanical insecticides that kill these pests. Thysanoptera (thrips) make an especially interesting case study in this field, because their increasing economic impact puts some urgency on the development of novel control strategies, especially strategies that incorporate natural compounds. Known facts about the host selection behaviour of thrips are briefly summarized, and methods for the evaluation of thrips responses to volatile and non-volatile plant compounds are outlined. Recent results on the search for attractive and repellent volatiles and for feeding and/or oviposition deterrent essential oil compounds are listed in detail and their potential for use in control strategies against thrips pests is discussed. An overview of plant essential oils used either for insecticidal spraying treatments of crops or for fumigation of crops in greenhouses or fumigation chambers completes the picture of bioactivities. Finally, an outlook on the perspectives for future control strategies against thrips pests is given, including thoughts on the direction of further research needed to fully evaluate the thrips control potential of plant essential oils.

Repellency of Essential Oils to <I>Frankliniella occidentalis</I> (Thysanoptera: Thripidae) as Affected by Type of Oil and Polymer Release

“…Although their results showed the potential of using a push-pull strategy, they remarked on the need to identify a suitable semiochemicals which have activity against western ßower thrips but not biological control agents. Although rosemary (Rosmarinus officinalis L.) leaves and volatiles were repellent in their study, rosemary oil is rich in cineole, and it has been observed previously that cineole could be an attractant to western ßower thrips (Koschier 2008). Presumably, the repellency of the essential oil from a particular plant species is inßuenced not only by variations in chemical constituents that are known to vary geographically but also according to the speciÞc volatile concentration perceived by the insect.…”

“…The concentrated population of the pest facilitates control (Cook et al 2007). This strategy is considered to have most potential in high-value horticultural production in enclosed environments (Cook et al 2007, Koschier 2008.…”

“…In a literature review by Koschier (2008), a list of volatile compounds attractive to adult Thysanoptera has been compiled. The list shows that western ßower thrips is attracted to various natural compounds including the monoterpernes (ϩ)-citronellol, 1,8-cineole, geraniol, linalool, linalool oxide pyran, and nerol, and the sesquiterpene (E)-␤-farnesene.…”

Hydrosols evaluation in pest control: insecticidal and settling inhibition potential against Myzus persicae (Sulzer)

“…Studies on the insecticidal or repellent activity of essential oils derived from plants within the family Lamiaceae have shown their potential against several insect pests (Hori ; Tunc and Sahinkaya ; Choi et al. ; Sedy and Koschier ; Akhtar and Isman ; Koschier ; Sajfrtova et al. ).…”

Toxic and behavioural effects of carvacrol and thymol on Frankliniella occidentalis larvae

“…Integrating the biological activity of secondary plant compounds as botanicals that kill pests or reduce their fitness or as allelochemicals that modify pest behaviour in conventional pest control strategies might mitigate this problem. Moreover, they can become interesting synergists for various biological control measures in integrated or organic farming systems in the future (Chiasson et al 2004;Kornherr et al 2005;Cook et al 2007;Isman 2008;Koschier 2008). Many aromatic plants produce secondary plant compounds as part of their biochemical defence system against herbivorous insects.…”