Fighting Drosophila suzukii with sage essential oil

14 Nov 2024
118

Small fruits are significantly threatened by Drosophila suzukii, an invasive pest that lays its eggs in ripe fruit, compromising its quality and shelf life. This problem is found in the Americas, Europe, Africa and Oceania, as well as Asia, and has become an important topic of study.

The reasons for the success of this midge lie in its wide host range, high fertility and short generation time. The main control strategy for D. suzukii is the application of chemical insecticides; however, resistance phenomena are developing due to the indiscriminate use of these chemicals. A potential alternative could be essential oils, but both their attractiveness and deterrence to this insect must be known.

Indeed, they can demonstrate powerful toxic and behavioural sub-lethal effects against a variety of pests, including D. suzukii. Sage (Salvia sclarea) essential oil is known to repel a variety of household and agricultural pests but the specific effect on D. suzukii remains uncertain.

In this study, conducted at Zhejiang University and the Provincial Centre for Disease Control and Prevention in Hangzhou (China), researchers implemented several behavioural assays to investigate the repellent properties of sage oil on larvae and adults of D. suzukii.

In addition, an analysis of the constituents of sage oil and an examination of the repellent effect of its main constituents, defined as linalyl acetate and linalool, was conducted to determine whether the repellency of the oil is conferred by these specific molecules.

Finally, the electro-anthennographic response of D. suzukii adults to clary sage oil and its two main constituents was examined. In this study, sage essential oil was found to exert a repellent function against D. suzukii adults and this was confirmed by the results of the two-choice attraction test.

Immagine 1: Risposte EAG degli adulti di Drosophila suzukii all'olio essenziale di salvia e ai suoi due principali costituenti. (A) Tracce EAG rappresentative suscitate da olio di salvia sclarea, linalolo e acetato di linalile alla diluizione 10−1. (B) Risposte EAG all'olio di salvia sclarea, al linalolo e all'acetato di linalile. Fonte: Yu Wang et al., 2024.

However, it is emphasised that this effect is dose-dependent. In addition, sage essential oil demonstrated a substantial repellent effect on D. suzukii larvae. Analysis of the chemical constituents of sage essential oil led to the identification of two main constituents: linalool (23.02%) and linalyl acetate (40.03%).

Furthermore, behavioural assays of linalool and linalyl acetate showed that both compounds exhibit a very strong effect against D. suzukii adults and larvae. It was understood that sage essential oil, linalyl acetate and linalool elicited electro-anthennographic responses in D. suzukii, of which sage essential oil was particularly effective.

This suggests that the chemical components of this oil were mediated by the olfactory system, triggering a repellent reaction. This shows that Drosophila exhibit olfactory avoidance behaviour. In conclusion, the olfactory and repellent response induced by sage oil and its two main constituents, linalool and linalyl acetate, are observed in D. suzukii adults and larvae.

This research not only establishes a basis for future mechanistic studies on the repellent effect of essential oils, but also offers evidence that sage essential oil and its main constituents may serve as viable alternatives for the control of D. suzukii.

Source: Wang, Y.; Wen, F.; Zhou, X.; Chen, G.; Tian, C.; Qian, J.; Wu, H.; Chen, M. Deterrent Effects of Clary Sage Oil and Two Major Constituents against Drosophila suzukii (Diptera: Drosophilidae). Insects 2024, 15, 733. https://doi.org/10.3390/insects15100733.
Images: Martin Hauser, California Department of Food and Agriculture; Yu Wang et al., 2024.

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

Uncertain outlook for the cherry market in Ukraine: frost and unstable weather jeopardise the 2024 season

Production

13 May 2024

‘I believe there will be few or many cherries this season, but with a lower price and less demand,’ says Oksana Gordiy, head of Umansk Fruit Company LLC. ‘Moreover, we cannot predict the situation with the war’.

Danese, a Hydrocooling System directly in the field

Post-harvest​ Quality

03 Nov 2023

The Veneto-based group, which has been involved in cold management for more than 35 years, is working on eliminating the time between the cherry's detachment from the plant and the moment when the temperature is lowered, with the 'Danese Hydrocooling System'.

In evidenza

The effects of calcium and silicon during cherry post-harvest storage

Post-harvest​

20 Nov 2024

Nowadays, there are various technologies and practices used to preserve quality by improving pulp consistency. It has been seen that pre-harvest or at harvest treatments with calcium and silicon extend the shelf life of cherries.

New Zealand: new Gisela rootstock selections approved for cherry growers

Planting systems

20 Nov 2024

Some dwarfing rootstock selections for Gisela® cherry trees have recently been licensed in New Zealand and will be more widely available to growers from 2026. Gisela® 12 and 6 are currently being tested in Central Otago.

Tag Popolari