In an effort to discover new and novel approaches to Mosquito Control, Manatee County Mosquito Control in collaboration with In2Care®, conducted extensive semi-field and field studies to evaluate the vector control potential of the In2Care Mosquito Trap on local populations of domestic mosquitoes such as Aedes aegypti.
This species is considered to be a primary vector of several viruses including yellow fever, dengue, chikungunya and Zika. Our research involved the utilization of the mosquito herself, where we put her to work. The idea is that the female mosquito visits the trap and picks up a biological larvicide called Pyriproxyfen, which they later transfer to nearby larval habitats as well as Beauveria bassiana spores that slowly kills the adults. We assessed the efficacy of the In2Care trap in reducing mosquito populations for multiple summers to see if this would be an effective mode of control for this species of mosquito.
The two graphs below show the counts of eggs and adults found in the treatment and control sites.
Long Distance Drift Study
For many years MCMCD has being studying ground deposition to determine the range of deposition after aerial ultra-low volume adulticide applications for use in evaluating the potential impact not only on mosquito populations, but on non-target organisms as well. In addition, the data is used to provide realistic operational conditions in comparison to spray-dispersion models that evaluate drift from aerial treatments. All of this allows us to ensure we are spraying in the right place, at the right time in the right amount.
What data are we looking for? (D.D.W.M.)
• Droplet size-spray clouds include a large range of droplet sizes, and we study this by using a program to read droplets from slides to determine droplet density and size.
• Deposition-how far does the spray cloud travel
• Weather-what is the optimal weather for spraying to reach the targeted mosquitoes
• Mosquito Mortality-Did it reach what we were trying to target?
Insecticide Resistance Monitoring
The use of insecticides to control mosquitoes in part of an integrated mosquito management program. This approach uses methods to kill mosquitoes based on mosquito biology, life cycle, and the way mosquitoes spread viruses. Mosquito Control districts conduct mosquito surveillance throughout the year to determine if and when control activities are necessary.
Over time, with repeated use of an insecticide, resistance can occur in mosquito populations. This means that the effectiveness of an insecticide is reduced allowing mosquitoes to survive after a spray mission.
In order to reduce resistance or prevent it all together, resistance testing is done annually; allowing us to detect resistance at an early stage so that we can make management decisions such as insecticide rotation.
To test resistance we conduct something called the bottle bioassay. A bottle is coated with a known amount of insecticide and mosquitoes are placed in the bottle and monitored for a period of time. Resistance is measured by the percentage of mosquitoes that die (mortality rate).
In Manatee County, we do resistance testing throughout the year and rotate our products regularly to prevent resistance.