Evaluation of hop (Humulus lupulus) as a repellent for the management of Drosophila suzukii

Abstract

Over the past decade, the spotted-wing drosophila, Drosophila suzukii Matsumara has become one of the most important pests of soft-and stone fruits throughout Europe. Currently, the majority of growers still rely heavily on a limited portfolio of chemical foliar spray insecticides. Alternative strategies such as attract and kill (pull) or behavioral control systems that repel or deter D. suzukii from damaging fruits (push) are less common. We evaluated the potential of hop (Humulus lupulus L.), as a repellent for the Integrated Pest Management of D. suzukii, in controlled greenhouse conditions as well as at commercial field sites. In greenhouse cage tests on fruit or attractant medium, the positive controls thymol and 1-octen-3-ol as well as certain hops significantly reduced larval infestation levels compared to an untreated control, while other hop products showed only numerical reduction in infestation. A controlled field trial on raspberries (Rubus idaeus L.) failed to replicate these results, both for the positive control repellents as for the hop samples. In field experiments in commercial raspberry and blackberry (Rubus fruticosus L.) plantations, no significant reduction in oviposition or differences in population density could be observed for the hop treated plots as compared to the untreated. Through SPME headspace analysis of the hops, a number of compounds were associated with the efficacy observed in the greenhouse, even though different hop varieties were found to have notably different volatile profiles.

Volatiles of bacteria associated with parasitoid habitats elicit distinct olfactory responses in an aphid parasitoid and its hyperparasitoid

“…Volatile compounds were identified and quantified as in Reher et al (). Briefly, chromatograms were analysed with amdis v2.71 (Stein, ) to deconvolute overlapping peaks, and obtained spectra were manually annotated using the NIST MS Search v2.0g software, using the NIST2011, FFNSC and Adams libraries, taking into account the expected retention time.…”

Bacterial phylogeny predicts volatile organic compound composition and olfactory response of an aphid parasitoid

“…An amount of 1.75 g NaCl was added to 5 ml of the samples and was kept at 60°C under constant agitation in a TriPlus RSH SMPE auto sampler. Volatile collection and separation conditions were as described previously (Goelen et al 2020a), and identification and quantification of the compounds was performed as in Reher et al (2019). Briefly, chromatograms were analysed using AMDIS ver.…”

Identification of Blackberry (Rubus fruticosus) Volatiles as Drosophila suzukii Attractants

“…GC-MS data of the blackberry samples were analyzed as described by Reher et al [ 7 ]. This resulted in 38 unique volatile compounds being identified.…”

“…The general way by which this pest is managed is via the routine use of broad-spectrum pesticides, which is costly, carries environmental risks, e.g., via carry-over effects on other beneficial insects, and disrupts the integrated pest management of other pests [ 5 ]. Other management options, such as exclusion netting [ 6 ], the use of repellents [ 7 , 8 , 9 , 10 ], sanitation [ 11 , 12 ] or mass trapping [ 10 , 13 , 14 , 15 , 16 , 17 , 18 ], have therefore been considered as more environmentally friendly alternatives. Unfortunately, up till now none of these has proven to be sufficiently effective in practice.…”