Field evaluation of Maqs® and Api-Bioxal® for late summer control of Varroa mite infestation in Northeastern Italy

The study evaluates the efficacy and effects of two organic acid-based miticides (Maqs® and Api-Bioxal®) used in late summer to reduce the population of Varroa destructor mites in colonies of Apis mellifera ligustica. The study took place in Albaredo d’Adige (Verona, Northeastern Italy). Twenty-six honey bee colonies, divided into four groups, were used for the experiment. Miticide efficacy, average daily mortality rate of adult bees, and number of bees present in the hives at specific timeframes were evaluated. The average daily efficacy of Maqs®’s miticide proved to be 96.8% compared to 93.4% for Api-Bioxal® combined with queen caging. High adult honey bee mortality was recorded after treatment with Maqs®, showing that average daily mortality was 82.4% higher than natural daily mortality. Daily mortality for Api-Bioxal® and queen caging was instead 30.1% lower than in non-treated colonies. The average decrease in the colony population of the treated groups was higher in the Maqs® (–38%) than in the Api-Bioxal® group (–28%). The fall in the latter was comparable to the values recorded in the control groups (–23% in the Api-Bioxal and –24% in the Maqs® control groups). Both veterinary medicinal products were effective for the control of V. destructor mite populations in late summer. However, the important negative effects recorded in the Maqs® group discourage the use of this miticide in geographical and climatic conditions of the type described in this study. Api-Bioxal® in combination with queen caging did instead confirm its efficacy and reliability for controlling the infestation in Northeastern Italy.

本研究评估了两款夏末用于防治意大利蜜蜂（Apis mellifera ligustica）蜂群内狄斯瓦螨（Varroa destructor）种群的有机酸类杀螨剂（Maqs®与Api-Bioxal®）的防效与应用影响。实验地点设于意大利东北部维罗纳省的阿尔巴雷多迪阿迪杰（Albaredo d’Adige）。本实验共纳入26群意大利蜜蜂，将其分为四组开展研究。实验评估指标涵盖杀螨剂防效、成年蜂日均死亡率以及特定时段蜂箱内的蜂群数量。实验结果显示，Maqs®杀螨剂的日均防效达96.8%，而联用囚王技术的Api-Bioxal®组防效为93.4%。使用Maqs®处理蜂群后，观测到较高的成年蜂死亡率，其日均死亡率较自然日均死亡率高出82.4%；与之相对，联用囚王技术的Api-Bioxal®组日均死亡率较未处理对照组低30.1%。在处理组蜂群的平均种群降幅方面，Maqs®组（下降38%）高于Api-Bioxal®组（下降28%），后者的种群降幅与对照组的记录值相当：Api-Bioxal®对照组下降23%，Maqs®对照组下降24%。两款兽药产品在夏末防治狄斯瓦螨种群方面均表现出有效性。但Maqs®组中观测到的显著负面影响，意味着在本研究所述的地理与气候条件下，不建议使用该杀螨剂。而联用囚王技术的Api-Bioxal®则证实了其在意大利东北部地区防治蜂螨侵染的有效性与可靠性。