瓦螨（Varroa destructor）是蜜蜂的体外寄生虫，卵圆扁平，红棕色，长1-1.2毫米，严重危害世界各地的西方蜜蜂（Apis mellifera）。瓦螨不但寄生在成蜂或幼虫上吸食体液，使其寿命缩短，而且还传播各种病毒和病菌。

东方蜜蜂（Apis cerana）在自然界中是瓦螨的原始寄主，有抗螨机制：咬断瓦螨的肢体，使其因失去体液而死亡。因此，东方蜜蜂不受到伤害。西方蜜蜂被引入东方蜜蜂原始产地，使瓦螨转移至西方蜜蜂寄生，进而传播至全世界，对养蜂业造成严重的危害。

Varroa destructor is an external parasitic mite that attacks the honey bees Apis cerana and Apis mellifera. The disease caused by the mites is called varroosis.

Varroa destructor can only reproduce in a honey bee colony. It attaches to the body of the bee and weakens the bee by sucking hemolymph. In this process, RNA viruses such as the deformed wing virus (DWV) spread to bees. A significant mite infestation will lead to the death of a honey bee colony, usually in the late autumn through early spring. The Varroa mite is the parasite with the most pronounced economic impact on the beekeeping industry. It may be a contributing factor to colony collapse disorder, as research shows it is the main factor for collapsed colonies in Ontario, Canada and the USA.