Myrtaceae Plant Essential Oils and their β-Triketone Components as Insecticides against Drosophila suzukii

Abstract

Spotted wing drosophila (SWD, Drosophila suzukii (Matsumura), Diptera: Drosophilidae) is recognized as an economically important pest in North America and Europe as well as in Asia. Assessments were made for fumigant and contact toxicities of six Myrtaceae plant essential oils (EOs) and their components to find new alternative types of insecticides active against SWD. Among the EOs tested, Leptospermum citratum EO, consisting mainly of geranial and neral, exhibited effective fumigant activity. Median lethal dose (LD50; mg/L) values of L. citratum were 2.39 and 3.24 for males and females, respectively. All tested EOs except Kunzea ambigua EO exhibited effective contact toxicity. LD50 (µg/fly) values for contact toxicity of manuka and kanuka were 0.60 and 0.71, respectively, for males and 1.10 and 1.23, respectively, for females. The LD50 values of the other 3 EOs-L. citratum, allspice and clove bud were 2.11–3.31 and 3.53–5.22 for males and females, respectively. The non-polar fraction of manuka and kanuka did not show significant contact toxicity, whereas the polar and triketone fractions, composed of flavesone, isoleptospermone and leptospermone, exhibited efficient activity with the LD50 values of 0.13–0.37 and 0.22–0.57 µg/fly for males and females, respectively. Our results indicate that Myrtaceae plant EOs and their triketone components can be used as alternatives to conventional insecticides.

Leptospermum scoparium essential oil is a promising source of mosquito larvicide and its toxicity is enhanced by a biobased emulsifier

“…These findings highlight the need to explore the potential for development and commercialization of L. scoparium essential oil as a mosquito larvicide. Most of the chemical constituents identified in this study have been reported in L. scoparium essential oil albeit at different quantities [9,13,16,35,36]. These differences are expected because the chemical composition of essential oils is known to vary by plant geographic origin, stage of development, growing conditions, developmental stage of the plant, method of extraction, solvent used for extraction, and photosensitivity of some compounds in the extract [36][37][38].…”

“…Leptospermum scoparium essential oil has been shown to be toxic against the spotted wing drosophila Drosophila suzukii Matsumura [16] and several species of mites [13][14][15][16], and also can synergize the activity of some essential oils against mosquito larvae [4]. Leptospermum scoparium essential oil has also been shown to be an attractive bait for the redbay ambrosia beetle, Xyleborus glabratus [17].…”

“…During World War II, L. scoparium essential oil was provided in the first aid kits of serving Australian soldiers for use as a general antimicrobial agent and insect repellent [10]. Other studies have demonstrated the toxicity of L. scoparium essential oil and some of its fractions against arthropods of economic and medical significance including the spotted wing drosophila Drosophila suzukii Matsumura, itch mite, Sarcoptes scabiei Linnaeus, poultry red mite, Dermanyssus gallinae De Geer, stored food mite, Tyrophagus putrescentiae Schrank, and house dust mites, Dermatophagoides farinae Hughes and D. pteronyssinus Troussart [13][14][15][16]. Leptospermum scoparium essential oil has also been shown to be an attractive bait for the redbay ambrosia beetle, Xyleborus glabratus Eichhoff [17].…”

Natural compounds for controlling Drosophila suzukii. A review

“…The contact toxicity of the non-polar fraction, made up of sesquiterpene hydrocarbons, was significantly lower than the toxicity of the polar fraction. The triketone fraction as part of the polar fraction was mainly composed of flavesone, isoleptospermone and leptospermone (Park et al 2017). For Leptospermum ericoides, the polar fraction was 67-fold more effective than the non-polar fraction for males and 134-fold more effective for females.…”

“…Among the tested substances, the most effective were Leptospermum ericoides and Leptospermum scoparium EO, the polar fraction of those EO and L. scoparium EO triketone fraction with LD 50 values between 0.13 and 0.71 μg/fly for males and 0.22 and 1.23 μg/fly for females (Fig. 2, Jang et al 2017;Kim et al 2016aKim et al , 2016bPark et al 2017Park et al , 2016. The contact toxicity of the non-polar fraction, made up of sesquiterpene hydrocarbons, was significantly lower than the toxicity of the polar fraction.…”