Separate and combined Hanseniaspora uvarum and Metschnikowia pulcherrima metabolic volatiles are attractive to Drosophila suzukii in the laboratory and field

R Jones,P E Eady,M R Goddard,M T Fountain,C S Günther

doi:10.1038/s41598-020-79691-3

Abstract

Drosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by individual fruit associated yeast isolates, but fruits naturally harbour a rich diversity of yeast species. Here, we report the relative attractiveness of D. suzukii to yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four of 12 single yeast isolates were attractive to D. suzukii, of which Metschnikowia pulcherrima and Hanseniaspora uvarum were also attractive in field trials. Four out of 10 yeast combinations involving Candida zemplinina, Pichia pijperi, M. pulcherrima and H. uvarum were attractive in the laboratory. Whilst a combination of M. pulcherrima + H. uvarum trapped the greatest number of D. suzukii in the field, the efficacy of the M. pulcherrima + H. uvarum combination to trap D. suzukii was not significantly greater than traps primed with volatiles from only H. uvarum. While volatiles from isolates of M. pulcherrima and H. uvarum show promise as baits for D. suzukii, further research is needed to ascertain how and why flies are attracted to certain baits to optimise control efficacy.

Highlights

Drosophila suzukii (Matsumra), known as spotted wing drosophila, is a damaging polyphagous pest that caused $511.3 million USD losses in three USA states in 2008 alone1
D. suzukii displayed significant differential attraction to the yeast isolates and individual binomial analyses of fly numbers attracted to each yeast isolate showed four were significantly more attractive to D. suzukii compared to sterile strawberry juice and, in decreasing order of attraction, these were: M. pulcherrima (AI = 0.36, P = 0.0005), P. pijperi (AI = 0.28, P = 0.0006), H. uvarum 201 (AI = 0.25, P = 0.0039), and C. zemplinina (AI = 0.06 P = 0.028)
D. simulans was differentially attracted to the yeast isolates (Δ deviance = − 21.52, df = − 12 P = 0.043, Fig. 1c), and individual binomial analyses suggest two of the yeasts were significantly attractive (H. occidentalis AI = 0.28, P = 0.0013 and P. kluyveri AI = 0.12, P = 0.010), but M. pulcherrima was significantly repulsive to D. simulans (AI = − 0.20, P = 0.0092)

Summary

Introduction

Drosophila suzukii (Matsumra), known as spotted wing drosophila, is a damaging polyphagous pest that caused $511.3 million USD losses in three USA states in 2008 alone. H. uvarum, Hanseniaspora valbenysis, M. pulcherrima and Torulaspora delbruckii were associated with D. simulans and D. melanogaster from two vineyard sites in Australia, and H. uvarum was the dominant yeast isolated from D. suzukii larvae and adults from US cherry orchards, followed by Issatchenkia terricola and Pichia kluyveri. H. uvarum, Hanseniaspora valbenysis, M. pulcherrima and Torulaspora delbruckii were associated with D. simulans and D. melanogaster from two vineyard sites in Australia, and H. uvarum was the dominant yeast isolated from D. suzukii larvae and adults from US cherry orchards, followed by Issatchenkia terricola and Pichia kluyveri22 These species, among others, were recovered from the larval frass of D. suzukii, again with H. uvarum being the most abundant. Yeast metabolic volatile compounds can diffuse through both yeast cell walls and air and appear to mediate Drosophila attraction, but the nature of chemical attraction is complex as it appears concentration, background and substrate dependent

Methods

Results

Conclusion