bug.latResearch summary · J Med Entomol 2020
Mosquito blood meal analysis: feeding habits in Harris County (Houston), TX
A plain-language summary of a 2020 study that used DNA barcoding to identify what vector mosquitoes in Harris County, Texas, fed on in 2018, and what that means for West Nile virus and mosquito control.
Key findings: what Houston mosquitoes feed on
- Diverse hosts. Mosquitoes fed on a diverse array of vertebrate hosts.
- Lots of birds. Bird (avian) hosts were used heavily, most surprisingly by species that usually favor people, such as Aedes aegypti.
- Mixed meals. About half of the specimens examined contained DNA from two different vertebrate hosts, suggesting many females took multiple blood meals in the same feeding cycle, in both urban and semi-urban locations.
- Backyard chickens. A high proportion of feeding was on domestic chickens, which may indicate that many homeowners raise chickens close to the trap sites.
Why mosquito feeding habits matter for public health
Blood feeding is a critical step in how mosquitoes transmit human pathogens. A mosquito picks up a virus from one host and can pass it to the next, so knowing which animals mosquitoes bite helps explain how diseases move through a city. The authors note that continuous surveillance of feeding patterns, especially in major population centers, is necessary for sustainable, effective control.
Chickens are non-amplifying hosts for West Nile virus. The paper suggests they may dilute West Nile virus transmission and have a zooprophylactic (protective) effect in their immediate vicinity. More about the virus is on the CDC West Nile virus page.
Spatial and temporal patterns in host use add insight into transmission dynamics, informing vector control strategies in Harris County and other metropolitan areas.
Methods in brief: DNA barcoding of blood meals
Female mosquitoes were trapped at locations across Harris County, spread among urban and semi-urban environments. The blood in each engorged mosquito was identified to host using a cytochrome c oxidase I (COI) DNA barcoding strategy: a standard gene region is sequenced and matched against reference sequences to identify the animal the mosquito fed on.
The work was a collaboration between the Department of Biology at Baylor University and Harris County Public Health’s Mosquito and Vector Control Division in Houston.
Authors
James G. Mann, Megan Washington, Taylor Guynup, Christopher Tarrand, Elizabeth M. Dewey, Chris Fredregill, Dagne Duguma, and R. Jason Pitts. Published in the Journal of Medical Entomology 57(6):1920–1929, November 2020.
Citation
Mann, J. G., Washington, M., Guynup, T., Tarrand, C., Dewey, E. M., Fredregill, C., Duguma, D., & Pitts, R. J. (2020). Feeding habits of vector mosquitoes in Harris County, TX, 2018. Journal of Medical Entomology, 57(6), 1920–1929. https://doi.org/10.1093/jme/tjaa117