Plant essential oils as potential control agents of varroatosis

Abstract

Beekeeping has always been vulnerable to various sanitary drawbacks. The mite Varroa destructor (Mesostigmata: Varroidae), an obligated ectoparasite of honeybees, has been in recent times one of the major problems leading not only to economical losses but also to ecological problems related to the role of honeybees as the most important pollinators on Earth. Varroatosis has been treated by methods that include special practices of beekeeping, physical removal, and the use of synthetic acaricides. None of these methods have, however, rendered complete protection, and there is clear evidence for the evolution of resistance to conventional acaricides. Consequently, the need for alternative control means has prompted the onset of several prospecting programs on botanicals with anti-varroa potential. Among these, essential oils appear as good candidates for safer control. In this review, we provide a concise compilation of the information generated in the last years on essential oils with anti-varroa activity. Future developments in this area demand standardization of bioassay protocols (either in the laboratory for primary screening or in hives), a detailed chemical characterization of the essential oils tested, and comprehensive studies on application methods.

Expression of heat-shock protein genes in Apis mellifera meda (Hymenoptera: Apidae) after exposure to monoterpenoids and infestation by Varroa destructor mites (Acari: Varroidae)

“…The development of novel miticidal compounds is essential in order to combat the increasing resistance of mites to conventional miticides. Hence, in the search for alternative miticides the miticidal activity of plant secondary metabolites has been evaluated (Colin, 1990;Greatti & Barbatinin, 1996;Ariana et al, 2002;Umpiérrez et al, 2011;Carayon et al, 2013;Singh, 2014;Li et al, 2017). It is well documented that plant essential oils can be used as fumigant miticides in the treatment of Varroa mites of which the monoterpenoids are probably the best-known (Carayon et al, 2013).…”

“…Different thymol-based formulations can be used to effectively control Varroa mites (Umpiérrez et al, 2011). A thymol-based varroacide signifi cantly alter the level of gene expression, metabolic responses including immunity, detoxifi cation and development in honey bees (Boncristiani et al, 2012).…”

Plant Essential Oils Used Against Some Bee Diseases

“…The mites causing colony problems in honey bees include species of Tropilaelaps (Laelapidae), the tracheal mite A. woodi (Tarsonemidae), and Varroa destructor Anderson and Trueman (Varroidae). Other mites encountered in honeybees are generally harmless or do not pose a great risk to honeybees (Umpiérrez et al, 2011). Among the diseases of honeybees, the parasitic mite V. destructor (Anderson and Trueman) is probably the most serious worldwide threat due to devastating effects to the beekeeping.…”

“…Essential oils were also reported to have repellent, deterrent and toxic effects on arthropods if applied via fumigation, topical use and ingestion (Umpiérrez et al, 2011). The mechanism of toxicity of essential oils on arthropods could be associated with cuticle disruption, molting and respiration inhibition, and reduction in growth and fecundity (Isman, 2000).…”

“…A. mellifera has been used by beekeepers to produce honey, wax and other apiary-related products, and has an important role in the pollination of native flora. Nowadays, eleven species are recognized with the genus, the other ones are less abundant ( (Umpiérrez et al, 2011). Honey bees are an established component of country's agricultural system.…”