Flower Foraging Dooms Mosquitoes as Nectar Spreads Honey Bee Virus to Bloodsuckers

Some mosquitos meet their fate when foraging as the honey bee virus can transmit via the nectar of a flower, effectively infecting bloodsuckers that feed on tainted blossoms.

Honey Bee Virus

Beekeepers face a serious threat from the black queen cell virus. When it infects honey bee larvae, it causes other pupal cells to turn black and eventually kills the larval queen. The virus has no known inhibitors beyond halting its spread and is capable of eradicating entire honey bee colonies.

Researchers at Brandon University in Canada, Cole Baril and PhDs Christophe LeMoine and Bryan Cassone, identified BQCV in a mosquito (Aedes vexans) using massively parallel next-generation sequencing, a technique for genetic sequencing. The scientists think that by foraging within the same nectar sources as infected honey bees, the mosquitoes unintentionally contracted the virus.

BQCV has been regarded as one of the most prevalent honey bee viruses since its discovery in 1955. It is also among the viruses that affect bees that are least well understood. Despite infecting both adult bees and queens, the black queen cell virus rarely causes symptoms in adult bees. It belongs to the picornavirus order and has an RNA genome with about 8,550 nucleotides. It is unclear exactly how the virus is transmitted from host to host. In addition to the Varroa mite and the microsporidia Nosema apis, adult honey bee foraging trips can also spread the disease.

Mosquitos

The researchers had been studying the genomics of various mosquito species in the prairie provinces of Canada. While searching, they discovered BQCV to their surprise among other new viruses as well as other microbial flora.

Using tiny light traps, the Brandon researchers captured mosquitoes in 2019 and 2020. The research team identified and isolated the RNA from Aedes vexans mosquitoes.

The newly discovered Canadian strain was compared to other viral genomes in the NCBI database to ascertain the evolutionary relationships between BQCVs. Indicating a foraging route of viral transmission, three sequences were mapped to plants, trees, and shrubs and matched to plant chloroplasts.

Mosquito Diet

Although nectar from flowers serves as a significant source of nutrition for mosquitoes, blood is still required for them to lay their eggs. According to the American Mosquito Control Association, sugar deprivation in females is associated with decreased survival and reproductive capacity.

However, there is no proof that BQCV can reproduce in mosquitoes, proving that the insects are a useless host for viruses. But more investigation will be required to ascertain whether mosquitoes can pass on the virus to honey bees.

The research by Baril, LeMoine, and Cassone was recently published in the Journal of Insect Science.

According to the study's authors, this is the first account of BQCV being discovered in mosquitoes or any other kind of dipteran. According to one theory, honey bees and these arthropods interact directly (through parasitism, predation, and scavenging) as well as indirectly (through foraging at the same nectar source).

Much is still unknown, according to Cassone. Although the virus has been discovered in North America, its genome sequence has never been characterized or previously found in mosquitoes. Cassone finds it surprising that not more research has been done on this virus given the potential negative effects it could have on apiculture, Entomology Today reports.