Asked July 22, 2016, 10:30 AM EDT

What is the Extension's best advice for the average homeowner to control mosquitoes in a swimming pool that is covered with canvas and therefore is collecting standing rain water. In the May 13, 2016 IPM Weekly Report on page 2 I read the news that the effective life of the Bti Mosquito Dunks is much less than advertised; and that Methoprene products have a longer persistence. Our community association is preparing our summer newsletter and we wish to address this issue with the best advice we can. Can you suggest an "easy solution for busy homeowners to manage their un-used swimming pools?" I will also check the AACO Health Department's information but I am counting on your advice.

Anne Arundel County Maryland

1 Response

An option you didn't mention is the use of a small pond pump (once a week when necessary) to drain off excess water on pool covers. Maybe one could be shared within the community?
For control, we highly recommend the Bti dunks.
The donut-shaped ones are slow release, and if they follow the label directions as to surface area of the water they should last a decent period. Certainly as long as they can see them there.
(The IPM report you refer to is produced for commercial green industry professionals who are also certified pesticide applicators, and the person who talked about it is from Colorado)

The problem involved with species like the Asian tiger mosquito is that they can reproduce in amounts of standing water as tiny as a teaspoon or less.
There are multiple places that can hold small amounts of water that we may not even think about.
Here is our page about mosquito control which includes links to the most current information from both the Maryland Department of Agriculture
The good news is that their breeding cycle can be disrupted by weekly draining, which can help control numbers.
Personal protections will also be key to dealing with mosquitoes.