There Are No Mosquitos At The Porch Light

2021 March 14

OK, this is in the nature of a public service announcement.

Let’s say you have a mosquito problem in your yard. And you go online looking for mosquito traps, to try to catch them and reduce their numbers. And you find that there are dozens, if not hundreds, of these traps available on the market.

But you note that the vast majority of them (and pretty much all of the less-expensive ones) are shown as glowing. Reading in a bit further, we see that they are using light as an attractant.

OK, fine. We all know that there are insects that are drawn to lights, so this seems reasonable. Except for one thing: are mosquitos, specifically, among the insects drawn to lights? Or, for that matter other biting flies (black flies, deer flies)?

Well, let’s find out, shall we?

Early June is prime mosquito and black fly season around here. If you step out in the yard that time of year, day or night, you’ll get mobbed by things that want your blood almost immediately. So, on June 9, 2020, I left the porch lights on. Then I went outside right around midnight to get pictures of what came to the light. And boy howdy, did a lot of things come to the light:



I see a bunch of moths, and midges, and little ichneumon and braconid wasps, and craneflies of various sizes, and even a lacewing. No mosquitos.

This brassy little beetle isn’t a mosquito, either.


Neither are these moths and their little friends.


This pair of midges is a cute couple, but nope, not mosquitos either.


OK, so how about these? There sure are a lot of them. Are they mosquitos?


Nope, apparently not. The little guys don’t even resemble mosquitos once we look closer, and the bigger ones turn out not to have the heads or beaks of mosquitos.


Going through all these pictures, out of literally hundreds of insects, I did not find a single one that is identifiable as a mosquito.




And on top of that, while there are no mosquitos on the wall or swarming around the light, I did start getting bitten by mosquitos while taking these pictures. The thing is though, I didn’t get bitten right away. It took a few minutes for them to show up. Which means that they were not already around the light. They had to smell me and hunt me down, from somewhere else!

So, here’s the problem: these light-lure mosquito traps are a scam. No question. Lights draw in pretty much everything except mosquitos. And yet, a lot of these things are getting 5-star reviews on Amazon, so people must think they are working. The problem is that, to the casual glance, a lot of the things being caught resemble mosquitos enough that the users (and, for all I know, the manufacturers), don’t know the difference. They never look closely enough to confirm that what they are catching are mosquitos[1], and just assume that they are. “Hey, I’m catching bugs by the bucket! The mosquitos must be in here too! It works great!” And they give it 5 stars, without ever stopping to notice that they are getting bitten by mosquitos just as much as ever.

This is supported by the fact that, if you look at the 1-star reviews for these light-lure traps, you see a lot of them who took the time to look at what they were actually catching, and noted that they are getting a lot of moths and such, but no mosquitos.

So please, please, please, don’t buy the light-lure mosquito traps.Any trap that depends on light of any sort to draw insects is not going to do what you want it to do.

The really unfortunate thing is, there are traps that use scents and warmed carbon dioxide plumes that actually do work. We used to have a Mosquito Magnet CO2-plume trap, and it caught actual identifiable mosquitos by the quart. The problem is that you may note I said “used to have” – the original Mosquito Magnets were expensive, temperamental and fussy to operate, and after about two years we couldn’t get them working any more at all. They could have been improved, but unfortunately the light-lure traps are cheaper to make and operate. And since people have been found to be perfectly willing to buy the light-lure traps, they are undercutting the sales and development of traps that actually have a prayer of working, and driving them off the market. As a horrible example of this, I just went to the Mosquito Magnet site, and what do I see? They have just acquired DynaTrap, one of the scam light-lure brands, and are selling them off of the Mosquito Magnet site! In spite of the fact that they don’t (and can’t) catch mosquitos as effectively as their original product! So it isn’t just a matter of the people buying them wasting their money, companies that sell mosquito traps are going where the sales are, and actual workable solutions are prevented from even being available.

This is all making me very sad. I think I am going to go ahead and make my own mosquito trap. What I will do is use one of my old CPAP masks to conduct my breath to a remote location, where it will act as a lure for a trap. This way, it is guaranteed that if anything is attracted, it will be things that want to bite me. Updates as things progress.

[1] To be fair, most people never get a chance to learn how to tell mosquitos from other insects. This is maybe something that should be included in middle school science classes: “how to tell if an insect is a mosquito”. In that spirit, let’s have a look:

My best mosquito pictures are on this page(even though I was mainly interested in the mites on her). Here’s a picture from that page:


Note the characteristic hunchbacked pose, and the long proboscis that she used to suck blood. Now compare this with a winter crane fly, which is a similar size:


Note that it is much less hunchbacked, and has no proboscis. Similarly, here’s a midge:


Again, less hunchbacked and no proboscis. And also big fluffy antennae, which mosquitos don’t have.

And someone might try to tell you, “Oh, the things you are catching with our light trap don’t look like mosquitos because they are male mosquitos! Catching the males will also be good, because then the females won’t be able to mate and lay eggs!”. One huge problem with this argument, though: Male mosquitos are also very distinctive. They look like this:


They also have very distinctive projections sticking out of their heads! So, basically, mosquitos have very distinctive features that distinguish them from all the other similarly-sized (but harmless) flies. If you are catching mosquitos, you can tell. And I can tell you, our porch light was not, repeat not, attracting mosquitos.

3 Responses
  1. Carole permalink
    March 14, 2021

    It’s easiest to go in at dusk to avoid being bitten by mosquitoes.

  2. March 15, 2021

    Could it be the case that incandescent light isn’t as big an attractor of mosquitos? They seem to be attracted to specific frequencies:,incandescent)%20light%20at%2024.9%20percent.

    Despite some traps using a specific frequency, there still seems to be significant bycatch, suggested by a comment to where someone was wanting to share that data with someone.

  3. March 15, 2021

    Tim: After looking at the link you gave, I am still dubious. The number they quote only shows the most effective (green) light as being about twice as effective as the incandescent light control. If that were the case, I would have expected to see some mosquitos at the light.
    The point that they are in Brazil is significant, too (and the next article you cite is in Florida). I expect they have completely different mosquito species there, and I concede that at least some of their mosquitos might be drawn to light. This does not appear to be true in northern Michigan, however.

    And the “significant bycatch” in the second link is kind of an understatement, based on what I’m seeing here. It isn’t catching a few moths, midges, and other harmless bugs for every mosquito caught. I would be catching hundreds, or even thousands, of harmless insects for every mosquito caught.

    Some of the people who reviewed the light-based traps on Amazon proudly put up pictures of what they caught. And every time, what I saw caught was a huge pile of moths, except for one guy whose “mosquitos” were a suspicious shade of green that made me think they were actually crane flies like these that I have caught from time to time.

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