Repellent and Antifeedant Activities of Citral-Derived Lactones against the Peach Potato Aphid

• Main Authors: Katarzyna Dancewicz, Antoni Szumny, Czesław Wawrzeńczyk, Beata Gabryś
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: International Journal of Molecular Sciences
• Subjects: lactones; terpene derivatives; antifeedant; aphids; probing behavior
• Online Access: https://www.mdpi.com/1422-0067/21/21/8029

Citral is well known for its antimicrobial, antifungal, and insecticidal activities. Natural sesquiterpene α-methylenelactones also exhibit a broad spectrum of biological activities. The aim of the study was to explore the effect of structural changes to citral molecules on citral behavior-modifying activity towards <i>Myzus persicae</i>. Specifically, the effects of the introduction of a γ-lactone moiety and methylene groups in α and γ positions of the lactone ring were investigated. The lactones were obtained in five-step (saturated lactone and γ-methylenelactone) or six-step (α-methylenelactone and α,γ-dimethylenelactone) syntheses from citral. The synthetic procedures and physical and spectral data of the lactones are presented. The settling behavior of freely moving aphids in choice and no-choice situations was monitored. The probing behavior of tethered <i>M. persicae</i> using the Electrical Penetration Graph (EPG) technique was also analyzed. Citral appeared a strong repellent and pre-ingestive and ingestive probing deterrent to <i>M. persicae</i>. The incorporation of a lactone moiety caused the loss of the repellent activity. α-Methylenelactone inhibited aphid settling and probing activities at pre-ingestive and ingestive phases. The saturated γ-lactone and α,γ-dimethylenelactone were the settling post-ingestive deterrents to <i>M. persicae</i>, which did not affect aphid probing activity. γ-Methylenelactone did not affect aphid behavior.