This past week I attended a lecture by Dr. Kristen Healy, an Assistant Professor of Medical Entomology and Public Health Entomology at LSU. Her presentation was on Arboviruses and how best to control their spread. Now some of you may be thinking that an arbovirus is a virus from the town of Arbo, Georgia, but actually an arbovirus is any virus carried by arthropods. Of course, the most common disease carrying arthropod is the mosquito, but other disease carrying arthropods include ticks and flies.
This is an arbovirus. Picture from http://dhmh.maryland.gov/laboratories/Pages/Arbovirus-and-Virus-Isolation.aspx.
Dr. Healy’s research over the years has been understanding how arboviruses spread by understanding how the arbovirus spread is related to mosquito reproduction. Understanding mosquito reproduction is no walk in a mosquito-free park either. As a mosquito researcher, Dr. Healy can’t just walk into a field a count the eggs in a nest, like for birds and snakes. She has to understand how numerous factors affect a mosquito population every year. These factors include the number of biting mosquitoes, host preference (how much they like humans), mosquito survival, and other things. (Side note: The number of biting mosquitoes is calculated by sending someone into the field and counting the mosquitoes that bite them over a set amount of time, CRAZY!)
OUCH! Picture from http://www.npr.org/sections/goatsandsoda/2016/02/22/465594861/why-zika-spreading-mosquitoes-love-ankles.
One of Dr. Healy’s early mosquito research projects focused on how best to tackle area wide mosquito control. Over the course of months, her and her team performed a massive area clean-up once a week, pouring water from containers and removing other containers and trash that could serve as mosquito breeding grounds. They also educated the people in the area by leaving pamphlets and providing door to door active education. Surprisingly, her research showed that the only thing that truly helped to control the mosquito population was the active education, not the area clean up or the passive education. Her research also showed that she could use GIS (geographic information system) to predict where tiger mosquito populations would be using population density.
Perfect for mosquito breeding. Not perfect for people. Picture from http://www.hudsonregional.org/mosquito/information.html.
Another research topic she is focusing on is if larvicide is more effective at certain temperatures during the year. She and some student researchers are looking to see what the critical temperature of Louisiana and New Jersey mosquito populations are how effect larvicides are at different temperatures. This research also provides us with the coolest term of the day: chill coma. The mosquito, instead of dying at cold temperatures, descends into a chill coma and waits till the temperature warms up to start moving again. The best analogy for this would be Captain America when he was frozen in the ice.
Chillin’ in a Coma like the Cap. Photo from https://www.scienceabc.com/humans/movies/captain-america-survive-frozen-ice-70-years-suspended-animation-cryonics.html.
Dr. Healy did provide us with a great take home message as well. All of her research into mosquito and arbovirus control has shown the importance for mosquito control programs to monitor and research how their effective their mosquito control techniques are in controlling the mosquitoes in an area. Spraying larvicides and adulticides without monitoring or understanding the process could be doing more harm than good or could be doing nothing at all. And remember, don’t forget to spray and neuter your mosquitoes.
by Richard Grabert