Mortality of phoretic Varroa mites and honey bees after feeding lithium chloride (LiCl) to caged bees. (a) Kaplan-Meier survival curve of female Varroa mites kept on caged bees fed with LiCl in concentrations between 2 mM–25 mM (n = 33, 9, 9, 12, and 9 cages for 0 mM (control), 2 mM, 4 mM, 10 mM and 25 mM, respectively). At all concentrations, the survival of mites in the treatment groups was significantly different from the control (P < 0.001, log-rank test with Bonferroni correction). (b) Kaplan-Meier survival curve of caged worker bees and female Varroa mites after 24 h LiCl exposure (n = 9 cages). The survival of mites in the treatment group was significantly different from the control group (P < 0.001, log-rank test) but there were no significant group differences in bee mortality.