Lithium chloride outperformed oxalic acid sublimation in a preliminary experiment for Varroa mite control in pre-wintering honey bee colonies

Abstract

Since lithium salts were demonstrated to be very effective for the potential control of Varroa destructor, a highly detrimental parasite of honey bee (Apis mellifera), no studies have been reported on their comparison with any commonly used varroicides in commercial bee colonies. In this study we compared the effectiveness of lithium chloride to that of oxalic acid, a widely used miticide. The results of the present study confirm that lithium has superior efficacy to oxalic acid sublimation both as a main or a supplementary pre-wintering treatment at moderate infestation levels, restricted to certain pre-wintering conditions. Considering its easy implementation in apicultural practice and its twofold mode of action, trickling would be the preferred way of administration after the use of lithium salts as varroicides is authorised.

Changes in Lithium Levels in Bees and Their Products Following Anti-Varroa Treatment

“…More extensive research is needed to determine lithium residues under field conditions in harvested honey and bee bread, as well as to determine a waiting time after the Li treatment. Further experiments are necessary to reveal how application methods like trickling [ 16 ] would affect the appearance of residues in honey, especially if performed repeatedly against the devastating pest V. destructor .…”

“…Being an obligatory social organism, a honeybee colony could actively reject aversive substances [ 12 ]. Moreover, feeding sugar syrup infused with varroacide is not typically the way of administering an anti- Varroa treatment in apicultural practice [ 16 ].…”

“…Lithium chloride (PubChem CID: 433294) may provide an effective, commercially available, and relatively cheap alternative, and therefore, it may be increasingly applied as an unregulated veterinary medicine [ 16 , 17 , 18 , 19 ]. Despite its potential to treat varroosis in the short term, only a few studies are dealing with the consequences of lithium treatments on honey and other bee products [ 15 , 20 ].…”

Varroa destructor from the Laboratory to the Field: Control, Biocontrol and IPM Perspectives—A Review

“…Ziegelmann et al [ 110 ] investigated its acaricidal impact by feeding honeybees and analysed their lifespan. This molecule, not yet on the market, showed efficient results against dispersal mites through oral and contact delivery methods [ 111 , 112 ]. However, the question arose about honeybee products potential contamination [ 113 ].…”

Frontiers in effective control of problem parasites in beekeeping

“…The major emphasis of this line of research is screening possible acaricide agents from elsewhere in agriculture or from prospective chemical analysis for use in varroa control, motivated by the challenges briefly discussed in section 2.4 . These efforts span both synthetic and non-synthetic sources, including simple pharmaceuticals such as lithium salts ( Kolics et al, 2021b ; Stanimirovic et al, 2021 ; Ziegelmann et al, 2018 ). Essential oil research remains of interest due to low regulatory hurdles (e.g.…”