Hey all,

I recently set up a rain barrel to catch water from my downspout to use around my garden. I threw in a 1/2 a mosquito dunk to deter mosquito larvae, but everytime I open the lid I see those little wrigglers dancing around and I get worried it's not working.

The dunks always seemed to work in my pond. I know the larvae are supposed to eat the dunk particles and that's the mechanism that makes them work, so I realize the fact that I'm seeing larvae doesn't mean they aren't working. Nevertheless, I'm worried.

Can anyone reassure me that I'm not unintentionally creating a mosquito haven? I have seen the occasional adult mosquito when I lift the lid, but she might just be laying eggs in the water and not actually have been spawned in my barrel, right?

Thoughts?

Thanks!

The dunks normally only work if the larvae eat them (some Bt will get in to the water but I too have seen mosquito larvae alive in tub ponds with dunks). Also, the Bt only kills the larvae when they molt their exoskeletons (so it's not an instant killer). If there's a lot of stuff for them to eat, they may not eat the dunks. The mosquito bits are smaller and more likely to be eaten. But, the best way to be sure they get a dose is to put in the Microbe-Lift liquid version. You can use both dunks and liquid to cover your bases. I have links to the products at http://www.fishpondinfo.com/mosquito.htm

Seeing flying insects when you open it doesn't mean they came from the barrel. They may not even be mosquitoes as a bunch of flies look similar.

Having a lid keeps out a lot of insects but they always seem to find a way in!

Good luck!