A disappointing observation

Tonight, I set up a white sheet in my yard, with a bright LED pointing at it, to see what insects would be attracted to it. It was pathetic.

After 45 minutes, 10pm to 10:45, all I found was a handful of moths, 20 or 30 tiny little flies, and about 10 mosquitoes. I’ll try again a different night with an additional UV light source, but this was mediocre. Nothing substantial enough to even feed an adult spider.


  1. StevoR says

    Is that a distinct change from previous attempts wit this method and worse than expected?

  2. John Morales says

    The opposite of unexpected.

    As I understand it, being a scientist and disappointing observations go together like… um, things that go together.

    (Buffy-speak FTW!)

  3. lasius says

    Try UV-LEDs! They always work very well for me, but are a bit stressing on the eyes.

  4. says

    This stuff is portable — a tripod, a sheet, a battery-powered LED — so I’m thinking I should make a trip to somewhere away from this pesticide-ridden rural area and see what happens. The catch: the whole damn state is plowed over.

  5. CompulsoryAccount7746, Sky Captain says

    @lasius #4

    Try UV-LEDs! They always work very well for me

    Insect Attraction to Ultraviolet-Reflecting Spider Webs and Web Decorations

    primitive spiders produce silks that reflect ultraviolet (UV) light and primitive aerial web weavers spin UV—reflecting catching silks that attract Drosophila.

    Derived, web-spinning spiders in the genus Argiope, however, produce catching silks that exhibit low reflectivity in the UV and, in fact, reflect little light at all. Nevertheless, Argiope decorate their webs with bright, UV-reflecting bars and crosses that attract prey. We found that more insects were intercepted per hour by decorated webs with spiders than by undecorated webs from which the spider had been removed. In addition, within-web analyses showed that when only half of a web was decorated, more insects were intercepted by the decorated halves than the undecorated web halves.
    One way in which insects use UV light is to locate open space. The sun and the sky are the only natural sources of ultraviolet light, and when insects fly from the interior of vegetation towards open space, they seek a UV-bright light gap. Silks suspended across vegetation gaps may attract prey by scattering both sunlight and sky light, making the gap appear bright in the UV region.

  6. Walter Solomon says

    When this is done in tropical rainforests, the amount and diversity of insects it attracts is astounding. You might just be in the wrong biome.

Leave a Reply