After doing some insect trapping last night, I noticed a lot of gnats flocking around my UV light trap. It got me thinking, are gnats naturally attracted to UV light like moths are, or is it another reason they were swarming?
That’s a good question, BugGuyBob! I think that UV light generally attracts a wide range of flying insects, not just moths, so it’s likely that gnats are also drawn to it. It probably has something to do with their navigation using natural light sources.
I can chip in here! Many insects are indeed attracted to UV light due to phototaxis, which is an insect’s automatic movement towards light. This is why UV light traps are so effective for pest control.
Actually, specific species of gnats are attracted to different wavelengths of light. Some prefer UV, while others might be more attracted to the blue or green part of the spectrum. It’s not just a one-size-fits-all situation.
Are all UV lights equally effective, or do gnats have a preference when it comes to the intensity or source of UV light?
Yep, that’s right. It’s due to the phototactic behavior of these insects. They navigate by UV light from the sun and can get confused by artificial sources.
Actually, UV light is known to attract many flying insects, including some species of gnats. They’re drawn to the UV spectrum, which can be used to lure them into traps.
I’ve got one of those UV bug zappers and it works like a charm. Definitely attracts those annoying gnats and zaps them.
My experience has been mixed. It seems to attract more moths than gnats. Might depend on the type of UV light and the specific gnat species in your area.
Gnats are more attracted to sources of heat and moisture. So the light itself might be less of a factor compared to the warmth it emits.
LED or not, I suggest you pair your UV source with a good lure, like CO2 or an octenol lure, to boost the trap effectiveness.
It’s more about the intensity and wavelength. Longer UV wavelengths seem to attract a broader range of night-flying insects, including gnats. It’s the UVA range (315-400 nm) that’s most attractive to insects. So, if you have a light that emits in this range, it’s gonna draw in gnats. But be careful, it can attract beneficial insects too!
@ScienceSteve Is correct about phototaxis. In my lab tests, fungus gnats show strongest attraction to 365nm UV wavelength. Different species have varying sensitivity though.
Not all UV lights are equal! Cheaper traps often use 395nm which attracts fewer gnats. Invest in quality 365nm units for best results.
@EntoErin Makes a great point about species variation. In my greenhouse, I’ve found blue sticky traps work better than UV for some gnat species.
Adding a small fan to your UV trap increases catch rates by 40%. Gnats get drawn to the light but can’t escape the airflow.
Commercial traps combine 365nm UV with 520nm green light for maximum gnat attraction. @BugGuyBob you might want to upgrade your setup.
Gnats swarm UV lights more aggressively during new moon phases when natural light is minimal.
Be cautious with UV traps near gardens. They can disrupt pollination by attracting beneficial insects too. I use them sparingly.
Research shows female gnats are more attracted to UV than males (likely due to egg-laying behavior). This affects trap effectiveness seasonally.