Why Are There Dragonflies on My Car?

Blue eyed darner, Rhionaeschna multicolor, flying

Blue eyed darner, Rhionaeschna multicolor, flying

I’ve been thrilled by the recent swell in the number of dragonflies out and about.  There are a lot of dragonflies flying this year, and they’re out earlier than usual.  Not everyone is happy about the glut of dragonflies though and several people have already written to me to ask how to get rid of the dragonflies in their yards.  I get several of those e mails every year, so that’s not unusual.  However, I’ve had a lot of people asking me why there are dragonflies hovering around their cars and that is odd.  I’ve responded to a good 15 e mails about this in the past week alone when I normally get somewhere between 2 and 4 a year.  Rather than typing out the same thing over and over to every individual who writes to me, I thought a blog post was in order.  So, today I give you the answer to the mystery of why there are dragonflies flying around your car!

Dragonflies require water to complete their life cycle.  The adults fly on land, but they start their lives in water.  Most dragonflies lay their eggs in water.  When they hatch, the nymphs develop underwater, feeding and growing until they are ready to molt into adults.  At that point, they crawl up a piece of vegetation or onto the shore, break out of their nymphal skin, puff out their wings, and fly away as a brand new adult.  Dragonflies spend the majority of their lives in water, often 10 months (or more!), before spending a month or two on land as adults.  Then they repeat the process and start the next generation.

For this to work, dragonflies have to be able to find bodies of water in which they can lay their eggs.  Luckily, they are able to do so!  They simply fly about and look for a particular pattern of polarized light.  When they see that pattern of light, they know that they’ve found water and can get down to the serious business of forming and defending territories, finding mates, and laying eggs.  That pattern of light is incredibly important for dragonflies, so it is highly attractive to them.

flame skimmer

Flame skimmer (Libellula saturata) resting on a car antenna

Unfortunately for the dragonflies, humans came along and started building cars.  Some of those cars give off the same pattern of polarized light as water, especially red or dark-colored cars.  As far as the dragonflies are concerned, a red or dark car IS a body of water because it gives off the correct light signature.  The result is that dragonflies mistake cars for bodies of water and go about doing what they normally do at water: making territories, finding mates, and laying eggs.  You might see a male dragonfly perched on your radio antenna.  He’s likely defending your car as his territory.  You might see two dragonflies mating above you car, indicating that a female decided that the “water” she found is an acceptable place to lay her eggs.  Sometimes you’ll just see a dragonfly bouncing up and down off the hood of your car.  That’s the female laying her eggs as she would in a pond.  Of course her eggs end up splattered across your car rather than in a pond, so they’re never going to hatch.  That’s bad for the dragonflies, and sometimes bad for you too.  Occasionally the eggs can cause minor damage to your car’s finish if they’re allowed to remain in place for extended times.

If you have a lot of dragonflies around you car, it’s best to try to discourage them from trying to lay eggs.  I have a white car and couldn’t care less about the finish (my vehicle is a field vehicle – you can tell), so let me state up front that I have very little personal experience with preventing dragonflies visiting my car.  However, I do have a few suggestions for things you can try:

1. Cover your car when it is not in use.  This is a huge pain, I know, and it makes you look like one of “those people” who are obsessive about protecting their cars.  However, if you are in an area where there is a lot of dragonfly activity and you repeatedly have problems with dragonflies laying eggs on your car (they’ll be visible as little yellow streaks or blobs), this is a surefire way to keep the dragonflies off your car’s finish.

2. Park in the shade whenever possible.  Parking under a tree will make your car less obvious from above.  It will also decrease the light hitting your car and reflecting off.  This should reduce the attractiveness of your car.

3. Try waxing your car.  I’m guessing here, but light reflecting off wax will likely have slightly different properties than light reflecting off the clear coat on your car.  It might be just enough to discourage dragonflies.  Wax should also add an extra layer of protection between the dragonflies and your car’s finish.

4. Start carrying a spray bottle of water and a rag or paper towels in your car to wipe off any eggs you see.  It’s easy to do a quick walk around of your car a few times a day and simply wipe away any eggs you find.  Getting them off your car as soon as possible should help minimize any damage the eggs might cause.

Yellowstone River

Natural water, where aquatic insects should lay their eggs

Discouraging dragonflies from visiting your car is a good thing.  Apart from the small risk of dragonfly induced damage, there is some real concern that the attractiveness of cars to dragonflies may eventually lead to a decrease in dragonfly populations.  Dragonflies need to find water to complete reproduction and they are unable to do so if they’re distracted by cars.  Some buildings, dark gravestones, solar panels, and other man-made objects are attractive to dragonflies too.  And dragonflies aren’t the only insects fooled by cars either!  Mayflies, horse flies, and other insects with aquatic stages have similar problems.  Eventually, we might need to reconsider how we build our buildings and finish our cars to protect aquatic insects, but anything you can do to discourage aquatic insects from mistaking you car for water is good for you and good for the insects – a real win-win for everyone!

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Additional Reading

György Kriska, Balázs Bernáth, Róbert Farkas, and Gábor Horváth.  2009.  Degrees of polarization of reflected light eliciting polarotaxis in dragonflies (Odonata), mayflies (Ephemeroptera) and tabanid flies (Tabanidae).  Journal of Insect Physiology 55: 1167–1173.

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Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth
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37 thoughts on “Why Are There Dragonflies on My Car?

  1. I don’t have dragonflies landing on my car, but deer flies do seem to like it, and I always wondered why (I presume it’s for a similar reason). As I approach the garage a horde of flies will descend and buzz around the car. And I thought they were waiting for me to get out!

    • It’s likely for similar reasons. A lot of horse and deer flies have aquatic or semi-aquatic immatures and are looking for water the same way the dragonflies are. They are likely to mistake your car for water too!

  2. We are thrilled the dragonflies have arrived in our yard. They seem much to busy to even notice the car – but we always park in the garage. Never knew car were such an issue for them.
    The cat is delighted they have returned and she now has entertainment almost constantly no matter which window she looks out.

  3. I was just observing this behavior this very morning! Dragonflies have always seemed to be attracted to our apartment complex parking lot and it makes a lot of sense considering their need for water and the light that reflects off of vehicles. I was honestly surprised to hear that they would be more inclined to frequent red or dark-colored vehicles. I figured cars lighter in shade or closer to the color of water would be the preferred object…a silver car parked next to me had maybe 2-3 dragonflies around it. There was one that seemed to enjoy bouncing off the surface of the vehicle’s hood…a female surmising from the information in your article. It was quite a spectacle to see.

    Since you mentioned the dragonflies being out earlier in the season does that mean they might be bigger this year too considering their extended time in season?

    • Dragonflies don’t really grow after they emerge from the water as adults, so they would have to start off as larger nymphs to end up becoming larger adults. If anything, the shorter nymphal period should make them a little smaller because they didn’t have as much time to hunt and grow as they normally would! It’s a good question though. That might be something worth looking into – if the size of the adults is related to the time of emergence. I’ll let you know if I find out anything more about it!

  4. Thanks for the great explanation. This past week I have seen lots of dragonflies as I commute to work (following a road that parallels the Potomac River). I don’t know if they are attracted to my car in particular (it’s an orange KIA Soul) but I guess I should check to see if the dragonflies are laying eggs on it.

  5. Excellent article! Thank you so much. I love dragonflies and do not have to worry about them laying eggs on my light-colored van. Plus, New Braunfels, has plenty of waterways for them to choose from.

    • Excellent! I live in an area with a lot of water too, but I still see dragonflies around cars now and again. I always feel a little sorry for them, so I’m glad to hear you have a light colored vehicle.

  6. So glad I found this blog post! For the past 3 weeks or so I have come out of work to find yellow deposits all over the hood of my car. I’m a car guy and like to keep it very clean, so this was getting on my nerves! I have noticed the large amount of dragonflies in the parking lot for a few years, and always thought it was funny how they would buzz my car when I pulled in. I immediately thought it was the dragonflies leaving these marks, but had no idea what it was. I was talking to a co-worker about it, and he told me he has seen them skimming the hood of his car while sitting in it for lunch. We did a quick search and ended up here. The funny thing about it is that no other cars around me have this problem, just mine. It is a metallic grey car, so maybe they think it is indeed water.

    • Apparently they do see it as water! And if you’re getting yellow splotches on your car, you’re getting females trying to deposit eggs. I know it’s annoying to have to clean them off constantly, but it really is better for your car’s finish to do so. Hopefully they’ll move on soon!

  7. I’ve seen dragonflies hovering over the hood of my car three times in as many weeks; my car is metallic grey/silver- I haven’t ever experienced this before with my other cars (other colors were light blue, navy blue, beige, maroon, green). Glad to see there’s some sort of explanation – and I really have enjoyed seeing them up close.

  8. Wow. This is so interesting and timely. I posted this pix recently on Bugguide. Give that car hood pix an extra click to really appreciate the patterns of those egg depositions :)

    • When you ask how long are they in egg-laying mode, do you mean how long into the season will they be out laying eggs like this or how long does each individual female lay eggs? The answer to the former: it could be another couple of months still, but there are more dragonflies out and in places you don’t normally see them at this time of year right now than usual too. It’s uncommon for this many dragonflies to be laying on cars like this, so the activity should die down again at some point, but it’s really hard to say when that might actually be. Each individual female only lays for a few minutes, but she’ll dip her abdomen in the “water” several times before she flies off. Each female might give you several of those streaks you see. Also, check out Cathy Wilson’s comment below this about the towels. That’s a great way to solve this problem – just cover up the hood when you’re not using the car and the dragonflies will look for another place to lay.

  9. Dragonfly Woman can best answer as to how long they lay eggs, but I am so glad I discovered that there can be a chemical reaction with the paint. That car hood belongs to a visiting friend. I was able to tell him to wash it off – frequently. Apparently an interaction can occur in as short a time as 3 hours! We then put beach towels across it and that seemed to discourage those poor confused spot-winged gliders.

  10. Thank you! I live in apartment building and have spent the past three summers watching dragonflies drop their seeds on car hoods. And I thought it was just pollen. I suppose this is why these love taps don’t wash off in a heavy rain.

    Perhaps there is a geographical component at work here. So, I’m in a small city in central Virginia, and I park in a lot. I don’t recall this happening in coastal Virginia. Same cars, but in a suburban driveway with overhead trees.

    I’m gonna pass this around on Facebook. I’m sure many of our neighbors have the same question. Again, thank you!!

    • It’s quite possible that this happens more often in certain types of urban areas than others. Hmmm… That would be something that would be really interesting to look into actually… Thanks for the idea!

  11. I have a pond and see dragonflies laying eggs by touching the pond with their ‘tail’ and I am wondering do the eggs need something to attach to or can the eggs just sink to the bottom? I see tons of mosquito larvae can they impact the success of the dragonfly eggs turning to nymths?

    • How a dragonfly lays its eggs is rather species-specific. The ones that touch their abdomens to the water as you observed tend to spray their eggs into the water and the eggs will sink to the bottom. Others fix their eggs in place by various means, but you would see those land and stay in one place for at least a few seconds, if not several minutes. The mosquito larvae shouldn’t impact the survival of the dragonflies, but I suppose it’s possible. Mostly I would consider them an excellent source of food for the dragonflies once they hatch and grow a little. :)

  12. I’m arriving to this dragonfly party a little late!! LOL I would like to know if the eggs off the car can be rescued and place in water to live? I want to encourage dragonflies in my yard.

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