DynaTrap vs Flowtron

They are not the same kind of machine

This is the distinction the whole comparison turns on, and the marketing on both boxes works hard to blur it.

A Flowtron is a bug zapper. Ultraviolet light attracts insects, and an electrified grid kills whatever touches it. The mechanism has no mosquito-specific element at all — it is a light, and it catches what a light catches.

A DynaTrap is a trap. It also uses UV light, but it adds two things a zapper does not have: a titanium-dioxide coated surface that warms and gives off carbon dioxide, and a suction fan that pulls insects into a retaining cage where they dry out. There is no grid and no snap.

That difference matters because of how mosquitoes find you. They are not drawn to light — they track exhaled CO2, body warmth and skin odour. A bright purple light is close to irrelevant to a host-seeking female mosquito, which is why a zapper's catch is overwhelmingly moths, midges, beetles and other harmless night-flying insects.

The evidence on zappers

This site earns affiliate commission on both of these products, so we will state the awkward part plainly.

Research published by the University of Florida Institute of Food and Agricultural Sciences found that electric bug zappers are essentially useless for controlling mosquitoes — the catch is dominated by non-target insects, and mosquito numbers in the treated area are not meaningfully reduced. That finding is decades old and has never been overturned.

So a Flowtron is not a bad product. It is a well-made product doing a job that is not the job most buyers have in mind. Our full treatment of this is do bug zappers work, and the head-to-head with the DynaTrap specifically from the zapper's side is bug zapper vs DynaTrap.

Side by side

Built from the manufacturer specifications of the units in the picks below.

A note on the coverage figures: both manufacturers quote up to an acre, and both numbers assume open ground. Hedges, fences, outbuildings and a house cut the effective radius down substantially, which is why two units placed well often beat one bigger unit in the middle.

Where the DynaTrap wins

It has a mosquito lure and the Flowtron does not. That is the decisive point. The CO2 surface is not as powerful as a propane-burning trap's output, but it targets the right cue.

It is quiet. No snap, which matters if the unit is anywhere near a patio you sit on or a bedroom window.

The catch is contained. You empty a basket into a bin rather than finding a layer of insect debris on the decking underneath.

It works indoors in a smaller form. The desktop version of the same fan-and-light design is genuinely useful on gnats and small flies in a room, which no outdoor zapper is. Best indoor mosquito traps covers that, and Katchy vs DynaTrap compares the two leading indoor units.

Where the Flowtron wins

Build quality. The BK-40D's housing survives seasons outdoors in a way a lot of this category does not. If you want a unit that is still working in five years, this is the one.

Raw kill volume on the insects it does target. On moths, midges and the cloud of flies that gathers around an outside light, a grid at full power is more effective than a fan.

Simplicity. There is no basket to empty and no fan to fail.

A real use case. If what is ruining your evening is clouds of midges or moths around the porch light rather than mosquito bites, the Flowtron is the correct purchase and the DynaTrap is not.

Neither of these is how you reduce mosquitoes

Here is the part that gets left out of every comparison of these two units: both are adult-stage interventions, and adults are the end of the process rather than the beginning.

A mosquito population is set by how much standing water it has to breed in. A female lays in anything holding water for a week or more — a clogged gutter, a plant pot saucer, a tarp fold, a bird bath, a kids' paddling pool, a tyre, a blocked drain. One neglected container can produce hundreds of adults. Trapping or electrocuting a fraction of the adults while the water keeps producing more is a treadmill.

The intervention that actually lowers the count is BTI — Bacillus thuringiensis israelensis, a naturally occurring bacterium that kills mosquito larvae and is harmless to fish, pets, birds and people. It comes as a floating dunk for water you cannot drain and as granules for scattering. The EPA's own guidance describes BTI as a mosquito control tool for larval habitat, and it is the reason a dunk appears in the picks above alongside two machines.

The order of operations, honestly:

1. Empty or treat every container of standing water on the property, weekly. This is the whole game.
2. BTI in anything you cannot empty — water butts, ponds, blocked low spots, tree holes.
3. A repellent zone for the hours you are outside, if you want tonight to be different. Thermacell vs bug zapper and mosquito trap vs repellent cover that trade-off.
4. Then a trap, for slow population pressure over weeks.

How to get rid of mosquitoes in your yard runs that sequence properly, and mosquito dunks vs bits picks between the two BTI formats.

The verdict

• Mosquito bites are the problem: DynaTrap, placed between the breeding area and where you sit, run continuously for several weeks — and treat the standing water first or the trap is doing the work of a bucket with a hole in it.
• A big yard, measured in acres: the larger DynaTrap, or two units rather than one.
• Moths, midges and flies around a light are the problem: Flowtron BK-40D. It is the better machine for that job and it will outlast everything else here.
• You want this evening to be different: neither. A repellent zone changes an evening; a trap changes a season. Best yard mosquito repellents.
• You have a pond, a water butt or a dog that drinks outside: BTI first, every time. Pet-safe mosquito yard sprays covers what else is safe around animals.