Do Other Types of Bees Get Mites, Too?
It is well known that Varroa destructor mites are one of the honeybee’s (Apis mellifera) worst enemies. Since Western honey bees do not possess the defense mechanisms to fend off non-native parasites, the mites can transmit deadly viruses to the bees. Seeing that Varroa mites have such a damaging effect on honey bees, numerous articles and research papers have been published to spread awareness, and the impact of mites on other types of bees, especially native bees, has been overlooked.
Do Varroa destructor mites affect other types of bees?
Since Varroa destructor mites have such an immense effect on honeybees, it is possible that their actions impact other types of bees that live in the same environments as the infected honeybees. Varroa mites originated in Asia, feeding on the Asian honey bee (Apis cerana). It was in 1962 when the first report of Varroa attacking Apis mellifera (a new host) surfaced in Hong Kong, China. Since then, the mite has shown up on every continent except for Australia through the transport of commercial bees, swarms that travel long distances, and migratory tendencies of beekeepers.
Varroa was first reported in the United States in September of 1987, when colony failure occurred in a few bee hives transported from Florida to Wisconsin. After this, Varroa’s presence was revealed in over a dozen states after beekeepers all over the nation began to check their hives. It seemed that there was no way to stop this disaster that was already so widespread, and records kept coming out reporting new finds of Varroa in the U.S.. The number of maintained honey bee colonies in the U.S. has been almost cut in half since the 1940’s as reported in the USDA-National Agricultural Statistics Service (NASS) annual survey.
Varroa mites can not successfully live on any other types of bees than Apis mellifera and Apis cerana, but scientists have discovered that the increase in infection rates of numerous viruses such as deformed wing virus (DWV) amongst honeybees affects other types of bees such as bumblebees, resulting in a shortened life span. DWV is one of the most widespread viruses by Varroa mites, and it damages bees’ wings so that they are unable to fly. The virus spreads when infected honey bees forage on the same plants as wild bumblebees in the same area. In addition to this, Varroa mites have been seen on bumblebees and yellowjackets to catch a ride from place to place. It is possible for them to feed on the larva of these bees; however the mites do not successfully reproduce on them.
Bumblebee Mites
Bumblebees (Bombus) are one of the few species of commercially developed pollinators, so from time to time they are shipped to different areas of the nation or the world for greenhouse pollination. During this trip they can be exposed to foreign parasites, such as Locustacarus buchneri. Locustacarus buchneri is an endoparasitic mite that has recently been found in commercial bumblebees. Endoparasites live inside their host and, in this case, they live inside the respiratory sac of queen bumblebees. Bees infected with Locustacarus buchneri have reduced life spans as reported in various studies. Commercial bumblebees usually forage outside the greenhouse as well, so they have the ability to transmit viruses to local, native bumblebees.
There are other mites associated with bumblebees that live and reproduce in bumblebee nests, however research for this has not been conducted on commercial bumblebees. These mites, such as Parasitellus fucorum, are basically harmless since all they do is eat old wax, pollen, and nest debris. These mites cling to bumblebees in order to travel to different nests, and the only potential harm is a bee being unable to fly because they are heavily infested with the mites.
Native Pollinator Mites
Native pollinators to North America, aside from bees, include butterflies, moths, beetles, flies, bats, and hummingbirds. All of these species are susceptible to parasitic mites and, surprisingly, most of the mites are harmless or even symbiotic. Butterfly mites have little to no effect on a butterfly’s flight performance, orientation ability, or lifespan. One common butterfly mite is Trombidium breei who attach themselves to the back of a butterfly and transfer from host to host when the butterfly stops to feed, similar to the Parasitellus fucorum hitchhiker mites on bumblebees. Moths are commonly infected by Dicrocheles ear mites, which colonize one of the moth’s two ears, leaving the other one functional to use echolocation. On the other hand, bats and hummingbirds have parasitic mites that are harmful.
The Importance of Bee Mite Relationships
Overall, it is evident that honeybees are not the only type of bee that gets mites. Parasitic bee mites can injure or kill their hosts and spread diseases, while some mites who may help clean or sanitize bees form symbiotic relationships. The Varroa destructor mite is evidently the most destructive to bees, especially honeybees, however there are thousands of other types of bees impacted by mites. Parasites are one of the most pressing threats to beehives, so it is important that beekeepers are well informed about different mite and bee interactions.