Castagna Fabio, Bava Roberto, Piras Cristian, Carresi Cristina, Musolino Vincenzo, Lupia Carmine, Marrelli Mariangela, Conforti Filomena, Palma Ernesto, Britti Domenico, Musella Vincenzo
Department of Health Sciences, University of Catanzaro Magna Græcia, CISVetSUA, 88100 Catanzaro, Italy.
Interdepartmental Center Veterinary Service for Human and Animal Health, University of Catanzaro Magna Græcia, CISVetSUA, 88100 Catanzaro, Italy.
Vet Sci. 2022 Mar 9;9(3):124. doi: 10.3390/vetsci9030124.
Varroatosis, caused by the mite, is currently the most dangerous parasitic disease threatening the survival of honey bees worldwide. Its adverse effect on the welfare and health of honey bees requires the regular use of specific acaricides. This condition has led to a growing development of resistance phenomena towards the most frequently used drugs. In addition, another important aspect that should not be understated, is the toxicity and persistence of chemicals in the environment. Therefore, the identification of viable and environmentally friendly alternatives is urgently needed. In this scenario, essential oils are promising candidates. The aim of this study was to assess the contact toxicity, the fumigation efficacy and the repellent effect of L. essential oil (EO) against mite. In the contact tests, each experimental replicate consisted of 15 viable adult female mites divided as follows: 5 treated with EO diluted in HPLC grade acetone, 5 treated with acetone alone (as negative control) and 5 treated with Amitraz diluted in acetone (as positive control). The EO was tested at concentrations of 0.125, 0.25, 0.5, 1 and 2 mg/mL. For each experimental replicate, mortality was manually assessed after one hour. The efficacy of EO fumigation was evaluated through prolonged exposure at different time intervals. After each exposure, the 5 mites constituting an experimental replicate were transferred to a Petri dish containing a honey bee larva and mortality was assessed after 48 h. The repellent action was investigated by implementing a directional choice test in a mandatory route. During the repellency tests the behavior of the mite (90 min after its introduction in the mandatory route) was not influenced by the EO. In contact tests, EO showed the best efficacy at 2 and 1 mg/mL concentrations, neutralizing (dead + inactivated) 90.9% and 80% of the mites, respectively. In fumigation tests, the mean mortality rate of at maximum exposure time (90 min) was 60% and 84% at 24 and 48 h, respectively. Overall, these results demonstrate a significant efficacy of EO against , suggesting a possible alternative use in the control of varroatosis in honey bee farms in order to improve welfare and health and, consequently, the hive productions.
由螨引起的蜂螨病是目前全球范围内威胁蜜蜂生存的最危险的寄生虫病。它对蜜蜂的健康和福祉产生不利影响，需要定期使用特定的杀螨剂。这种情况导致蜜蜂对最常用药物的耐药现象不断增加。此外，另一个不应被忽视的重要方面是化学物质在环境中的毒性和持久性。因此，迫切需要确定可行且环保的替代方案。在这种情况下，精油是很有前景的候选物。本研究的目的是评估罗勒精油（EO）对蜂螨的接触毒性、熏蒸效果和驱避作用。在接触试验中，每个实验重复由15只存活的成年雌螨组成，分为以下几组：5只用HPLC级丙酮稀释的EO处理，5只只用丙酮处理（作为阴性对照），5只用丙酮稀释的双甲脒处理（作为阳性对照）。EO在0.125、0.25、0.5、1和2mg/mL的浓度下进行测试。对于每个实验重复，1小时后人工评估死亡率。通过在不同时间间隔进行长时间暴露来评估EO熏蒸的效果。每次暴露后，将构成一个实验重复的5只螨转移到一个装有蜜蜂幼虫的培养皿中，并在48小时后评估死亡率。通过在强制路径中进行定向选择试验来研究驱避作用。在驱避试验期间，螨（引入强制路径90分钟后）的行为不受EO的影响。在接触试验中，EO在2mg/mL和1mg/mL浓度下表现出最佳效果，分别使90.9%和80%的螨中和（死亡+失活）。在熏蒸试验中，在最长暴露时间（90分钟）时，24小时和48小时的平均死亡率分别为60%和84%。总体而言，这些结果表明EO对蜂螨具有显著效果，这表明在蜜蜂养殖场控制蜂螨病方面可能有替代用途，以改善蜜蜂的健康和福祉，从而提高蜂群产量。
