The role of yeasts in the life cycle of Drosophila suzukii

07 Oct 2024
2078

New cherry pest management strategies are being developed in response to the need of reducing the use of insecticides and preventing the emergence of resistant populations. Associations between D. suzukii and microorganisms, particularly yeasts, have provided valuable information, paving the way for more environmentally friendly methods.

These methods consist of traps, push-and-pull and attract-and-kill methods. The latter approach has the potential to improve the reduction of oviposition and mortality of this harmful insect. There are numerous interactions between various drosophilid species and yeasts.

For example, Drosophila melanogaster is linked to Saccharomyces cerevisiae, the yeast commonly used in bread-making, and D. suzukii is linked to Pichia terricola, Pichia kluyveri and Hanseniaspora uvarum. Previous studies have identified H. uvarum on both grape and raspberry fruits infested with D. suzukii.

Another interesting aspect is the presence of this yeast in the central part of the intestine of D. suzukii larvae and adults. The objective of the investigation carried out by researchers from different institutes in Italy and Germany was to study the efficacy and applicability of an attract-and-kill formulation in the context of sweet cherries. The same strain of Hanseniaspora uvarum LB-NB-2.2 that had previously been shown to be effective in grape crops.

The effectiveness of the attract-and-kill approach was evaluated under different infestation pressures, on various training systems and under varying climatic conditions by conducting field trials at four different locations over a three-year period.

In addition, the potential of the attract-and-kill method to reduce the amount of insecticide administered was analysed. Finally, the potential for reducing spinosad residues on the fruit as a result of implementing this control strategy was also evaluated. In six field trials conducted in Italy and Germany to manage D. suzukii infestations in cherry trees, the chemicals under investigation were applied over an area of 80-100 cm starting at 1 m height (i.e. only the lowest part of the canopy was treated).

The percentage of cherry trees infested by D. suzukii decreased between 42% and 84% and the average number of eggs deposited decreased by 80-96% when the attract-and-kill formulation was applied at a dose of 21.6-34.9 g per hectare of spinosad, depending on the form of cultivation.

The efficacy was comparable to that of the conventional application of spinosad alone, applied at a dose ranging from 84 to 216 g per hectare. Conventional application resulted in a 77% to 93% reduction in the number of eggs laid and a decrease in the percentage of affected cherries by up to 92%.

By concentrating the application of insecticides on a restricted area of the cherry tree, the attract-and-kill technique reduced insecticide use by up to 90%. The targeted approach not only reduced the amount of insecticide per hectare, but also resulted in lower residue levels on treated products.

In six field trials at four different locations, our investigation examined the effectiveness of an attract-and-kill strategy for the management of D. suzukii in sweet cherry orchards. The results obtained underline the effectiveness of this method in reducing both insecticide applications and infestations, providing a promising alternative to conventional pest management methods.

In summary, the attract-and-kill strategy succeeded in achieving a sustainable and efficient solution for the management of D. suzukii infestations in cherry plantations.

Source: Marko Bjeljac, Urban Spitaler, Nicola Mori, Matteo Fusillo, Enea Bombardini, Michele Preti, Stefano Caruso, Giacomo Vaccari, Astrid Eben, Andrea Lentola, Sergio Angeli, Silvia Schmidt, Canopy strip applications of Hanseniaspora uvarum combined with spinosad reduce insecticide use without compromising Drosophila suzukii control in cherry, Crop Protection, Volume 186, 2024, https://doi.org/10.1016/j.cropro.2024.106868.
Image: Marco Bjeljac

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

From Germany to the USA: the KIR™ series exclusively at Brandt's Fruit Trees

Varieties

24 Jul 2024

‘Our company has been granted exclusive propagation rights in the US for the KIR™ series of sweet cherries,’ reports Kevin Brandt. Three of the most advanced selections have already been branded with the trade names KIR Rosso®, KIR Lamour® and KIR Vulcano®.

WSU cherries: optical sorter transforms cherry breeding in Washington

Breeding

15 May 2025

Washington State University is transforming cherry breeding with an advanced optical sorter. Faster, more precise and objective analysis of fruit traits—such as size, color and defects—brings major benefits to varietal selection and lab efficiency.

In evidenza

An early harvest and good quality for South African cherries. A 50 per cent drop in production is forecast

Production

11 Nov 2026

South Africa’s cherry harvest season began two to three weeks early, but production in Ceres could fall by over 50%. Heat and cold during flowering affected fruit set. Early cherries reach 30 mm, while Tru-Cape aims to increase exports from 15% to nearly 20% of its crop.

The government of Extremadura is allocating aid of up to 1,500 euros per hectare to cherry growers

Production

11 Nov 2026

Nel 2026 l’Estremadura approva 19,59 milioni di euro di aiuti per cereali, ciliegie e apicoltura: fino a 50 euro per ettaro irriguo, 1.500 euro per ettaro di ciliegio e 18 euro per alveare. Le pratiche saranno avviate d’ufficio e i pagamenti sono previsti entro fine anno.

Tag Popolari