Biological Activity of the Salvia officinalis L. (Lamiaceae) Essential Oil on Varroa destructor Infested Honeybees

Abstract

The present work is conducted as part of the development and the valorization of bioactive natural substances from Algerian medicinal and aromatic spontaneous plants, a clean alternative method in biological control. For this purpose, the bio-acaricidal activity of Salvia officinalis (sage)essential oil (EO)was evaluated against the Varroa destructor, a major threat to the honey bee Apis mellifera ssp. intermissa. The aerial parts of S. officinalis L., 1753 were collected from the Chrea mountainous area in Northern Algeria. They were subjected to hydro distillation by a Clevenger apparatus type to obtain the EO, and screened for bio-acaricidal activity against Varroa destructor by the method of strips impregnated with the mixture EO and twin according to three doses. Pre-treatment results revealed infestation rates in the experimental site ranging from 3.76% to 21.22%. This showed the heterogeneity of infestations in hives according to the density of bees. This constituted a difficulty in monitoring the population dynamics of this parasite. After treatment, a difference in the acaricidal effect of Sage essential oil is noticed. It gives a mortality rate of 6.09% by the dose D1: 5%, 2.32% by the dose D2: 15%, and a low mortality rate of 0.9% by the dose D3: 20%. The chemical treatment carried out by Bayvarol gives a result close to that of the essential oil of Sage (9.97%).These results point to the fact that Sage essential oil treatments have a significant effect and good biological activity with regard to harmful species.

Varroa destructor: how does it harm Apis mellifera honey bees and what can be done about it?

“…Lithium chloride has also been demonstrated as a potential compound against Varroa [97], as well as other essential oils and their combinations [98]. Recently, Bendifallah et al [99] demonstrated the biological activity of sage essential oil as a Varroa control. However, currently there are no registered products available based on these new bioactive sources.…”

Some essential oils as potential control agents for varroa mite (Varroa destructor) in infected honey bees (Apis mellifera)

“…Several components derived from plants, including plant oils, have been shown to have biocidal activity ( Masry et al, 2020 ; Sabahi et al ., 2020 ). These compounds are thought to be more environmentally friendly acaricides and have been investigated as potential varroa mite control ( Imdorf et al , 1999 ; El-Hady et al ., 2015 ; Abu Bakar et al ., 2017 ; Bendifallah et al ., 2018 ; Kadhim et al ., 2022 ). Approximately 150 essential oils have been evaluated in laboratory screening tests ( Imdorf et al , 2006 ; Bava et al , 2023 ) very few of them, however, have proven successful in controlling V. destructor when tested in field trials.…”

Acaricidal activity of essential oils for the control of honeybee (Apis mellifera) mites Tropilaelaps mercedesae under laboratory and colony conditions

“…Formic acid and thymol have both been shown to have efficacy against Tropilaelaps (Raffique et al 2012;Pettis et al 2017). Also, several essential oils have demonstrated acaricidal efficacy in controlling Varroa mites, such as Syzygium aromaticum , Acantholippia seriphioides , Schinus mole , Citrus aurantium , Cymbopagon flexuosus , Thymus vulgaris , and Salvia officinalis (Ruffinengo et al 2005;Abd El-Wahab and Ebada 2006;Damiani et al 2009;Gashout and Guzmán-Novoa 2009;Bendifallah et al 2018). As alternative control methods, essential oils have shown high acaricidal activity and low toxicity to bees.…”