Adulticide treatments occur near sunset when mosquitoes are most active and sprays can be the most effective. In the summertime that can mean 10 pm or later. Depending on the application method you may or may not even hear or see the vehicle. Aerial applications are conducted with either a helicopter (rural areas) or airplane (urban areas) and have a swath width of 1,000 feet. The aircraft may not even fly over your property, but you are being treated. Ground vehicles drive past your property going 10-15 mph and avoid doubling back on themselves.
Larvicide treatments occur throughout spring, summer and fall, but typically occur in unpopulated areas, so those are also not very visible. Larvicide treatments also occur via air and ground. Aerial applications often take place just after dawn or before sunset when weather is calm. Ground applications often use residual products that are effective for 3 to 4 weeks, so even if an area is wet, it likely has already been treated.
Larvicides are much more effective than adulticides for two major reasons:
- Immature mosquitoes (larva) are only found in standing water, and
- The pesticides we use are very specific to mosquito larva.
Adulticides are less specific to mosquitoes, are susceptible to weather conditions, and necessitate that an adult mosquito must encounter a spray droplet. Mosquito adulticides offer no residual activity and are quickly rendered inert when exposed to sunlight. However, both components are part of an integrated vector control program and accomplish very different tasks.
Read more about treatments on our Types of Vector Control webpage.