biting flies on Long Island Sound

[jg]

Don't know if this is the correct Board to post this on. There are times on Long Island Sound when swarms of biting flies take over the cockpit and cabin of our 40 DS. It really is overwhelming and the bites are quite painful. Once in the cabin they are hard to get rid of. Any ideas would be appreciated.

[Zanshin]

I had one attack with a cabin full of those pesky critters when I was taking my boat from Newport to Annapolis. They really are a pest!

I purchase 36.8% Permethrin by the gallon. Then dilute it to 0.5% and put in a spray bottle. This gets sprayed on all soft surfaces such as cushions, Sunbrella, hats, bedsheets, clothing. It can go on hard surfaces such as countertops or wooden panelling, but just doesn't last as long.

Permethrin doesn't work as an insect repellent. It kills them, on contact. Even cockroaches will succumb (given time). It is great stuff and non-toxic to humans and dogs. It is toxic to cats, though. The U.S. Military has been infusing their BDUs and other items with Permethrin for years; DEET is just too caustic.

Permethrin degrades slowly in UV, but you can do the math to see how far one gallon will go.

I've got a link to a U.S. Army study at Zanshin Sailing First Aid and Medical

[Chris Meyer]

Jul 10, 2023 13:51:59 GMT jg said:

Don't know if this is the correct Board to post this on. There are times on Long Island Sound when swarms of biting flies take over the cockpit and cabin of our 40 DS. It really is overwhelming and the bites are quite painful. Once in the cabin they are hard to get rid of. Any ideas would be appreciated.

I buy Home Defense by the gallon.   It now has a battery powered spray wand.   I made sure the boat is clean and then spray all around the boat.   Seems very effective for spiders and other insect.

Also, we found that flies are the worst after we eat lunch in the cockpit.  Might try not allowing food in the cockpit for some time.

[Zanshin]

The active ingredient in Home Defense is Bifenthrin. That and Permethrin are members of the pyrethroid group and are similar in how they work. I got a chuckle reading the MSDS for Home Defense, they are quite cagy in putting that document together and it reads as if it were about as toxic as water.

[jg]

I think the flies come even if there has been no food in the cockpit but will be extra careful about that. Have wanted to avoid products with Permithrin but may have to reconsider. Thank you for letting me know it works, though, and for your reference.