By Kent Taylor, Co-Owner & Lead Screen Specialist, Cheetah Screens | Jacksonville, Florida
You did everything right. You have a covered lanai, it’s screened in, and you still walk inside at dusk with three new welts on your ankles. The frustrating part is that you often never see what bit you. You just feel it the next morning.
I hear this constantly across Jacksonville, St. Johns, and the beaches. People assume a screen is a screen, so if the bugs are still getting through, the screen must be broken. Usually it isn’t broken at all. It’s just the wrong screen for the bug you’re fighting.
The bug you can’t see is probably a no-see-um
The number one culprit in Northeast Florida is the no-see-um, also called a biting midge or sand gnat. These things are tiny, roughly one to three millimeters, small enough to fly through the openings in a standard insect screen the way a marble goes through a chain-link fence. Standard screen is a 18-by-16 mesh, meaning 18 openings per inch in one direction and 16 in the other. A no-see-um fits through that opening without slowing down.
The fix is a tighter mesh, and that product exists. It’s called no-see-um screen or 20-by-20 mesh, which means 20 openings per inch in both directions. The openings are small enough that no-see-ums and most other tiny flies can’t get through. You can also go to a 17-by-14 specifically rated for fine insects, but 20-by-20 is the most common solution and the one I recommend most often.
The second problem: gaps at the edges
Mesh is only half the battle. A tight weave doesn’t help if there are gaps at the edges, corners, or where the screen meets the track. Bugs don’t fly through the screen. They walk through the gap you can’t see. This is why a motorized retractable screen in a proper sealed track system outperforms a screen stapled into a frame when it comes to bugs. When the fabric rolls all the way down and seats into the track on both sides, there’s no gap to enter through.
If you’re still getting bitten on a screened lanai with standard fixed screens, look at the corners and the edges before you assume the screen is the wrong mesh. Tears and separations at the frame are common after a few years, especially in our heat, and a no-see-um will find a pinhole-sized gap immediately.
Mosquitoes and lovebugs: a different problem
Mosquitoes are bigger than no-see-ums and they don’t generally pass through standard screen. If you’re getting mosquito bites on your screened lanai, the issue is almost always a gap, a torn screen, or a door that doesn’t close fully. Fix the seal before you upgrade the mesh.
Lovebugs deserve a special note because they cause a second problem beyond annoyance. Their residue is mildly acidic, and if it bakes onto a track or a finish in our sun for a day or two it can leave a mark. The fix is easy: rinse them off promptly with mild soapy water and a soft cloth, and never scrub a screen or track with an abrasive pad. Keeping the tracks clean also keeps a motorized screen operating smoothly.
Two small habits that stack on top of the screen
A good sealed screen with the right mesh solves most of the problem. If you want to go further, two cheap habits help.
First, run a ceiling fan or even a standing fan on the lanai. No-see-ums are weak fliers. Even a modest breeze — three to four miles per hour — keeps them from landing on you. Most screened lanais that get regular use already have ceiling fans, and just turning them on at dusk cuts bites significantly.
Second, keep standing water off the property. Mosquitoes breed in anything that holds water, including low spots in flowerpots, gutters, and bird baths. Eliminating standing water within your control reduces the mosquito population in your yard, which reduces the number trying to find a way in.
Frequently asked questions
Will any screen completely keep out no-see-ums?
No screen guarantees zero bugs, but a 20-by-20 no-see-um mesh in a fully sealed track system stops the vast majority of midges and gnats. The seal matters as much as the mesh.
Does tighter mesh hurt airflow on my lanai?
A little. No-see-um mesh moves slightly less air than standard screen because the weave is denser, but it also cuts wind and adds privacy. With a ceiling fan, most homeowners don’t notice a difference in comfort.
Do I need no-see-um mesh if I’m not near the beach?
Often yes. In Northeast Florida, ponds, retention basins, the Intracoastal, and the St. Johns River all breed midges, so distance from the ocean doesn’t mean you’re safe. If you’re near any standing or moving water, no-see-um mesh is worth considering.
Still fighting bugs on your lanai? Contact us for a free consultation and we’ll seal it up right. — Kent