Entries tagged with “moths mercury vapor black lights” from Bugs in the News
Ever wonder why they do it? Night flying insects like moths, beetles, caddisflies and others are always hanging around your porch light like ticketless tweens outside a Hannah Montana concert. Well, scientists aren't too sure either, but they have some good theories.
When you're taking a walk or riding in the car at night where you can see the moon, it seems to travel alongside of you no matter where you go - but it also remains a point of reference in the sky. That is, if you are walking with your left side to the moon and turn around, the moon is then on your right side. Duh.
This is how moths (and other night flyers) do it; they use the moon to navigate, keeping the bright moon just over one wing or the other. If the moth got to point A with the moon over its right wing it knows to go back from where it came by flying with the moon over its left wing. So the rule of the game is to keep the moon to one side and you know you're flying (or walking in our case) in a straight line.
So what does this have to do with porch lights? Why are they flying into them? If you took a walk by a porch light or streetlight with the light to your right and started to walk eventually you would have the light behind you. Since the rules are to keep the light along side of you,
you'll need to turn slightly so that the light is once again by your shoulder. But yes, you're right - now you've moved off of your straight course. Keep doing this over and over and you will be moving in a circle around the artificial light. Shorten the distance of each circle and you will find yourself face to face with the soft glow of a Westinghouse.
Scientists use this behavior to their advantage: it's one good way to collect insects that normally are hiding during the day. In many cases two kinds of lights are used: a mercury vapor or a black light (yes, same one your roommate used to light up the velvet poster of Jim Morrison). Hang one of these in front of a white sheet and the glow will be irresistible for the nighttime navigators.
A number of years ago when I was in graduate school at Georgia Southern University I was enrolled in an entomology class with the amazing Dr. Frank French. One of our assignments was to create an insect collection. A few days before the due date I found myself a bit short of the required number of specimens. Well, later that night I wandered over to the lights used to illuminate a billboard at the intersection of highways 301 and 25. Jackpot - there were literally layers upon layers of insects; living, dead, confused, preying on others - it was sweet madness. Needless to say thanks to the bright lights I finished my collection that night.
What's good for collectors is ultimately not good for the moths - not that the act of collecting itself is doing much of any harm but the prevalence of high-powered mercury vapor and sodium lights attracts moths away from the forests and shelter and into the mouths of birds who are up just before the sun shines.
When you're taking a walk or riding in the car at night where you can see the moon, it seems to travel alongside of you no matter where you go - but it also remains a point of reference in the sky. That is, if you are walking with your left side to the moon and turn around, the moon is then on your right side. Duh.
This is how moths (and other night flyers) do it; they use the moon to navigate, keeping the bright moon just over one wing or the other. If the moth got to point A with the moon over its right wing it knows to go back from where it came by flying with the moon over its left wing. So the rule of the game is to keep the moon to one side and you know you're flying (or walking in our case) in a straight line.
So what does this have to do with porch lights? Why are they flying into them? If you took a walk by a porch light or streetlight with the light to your right and started to walk eventually you would have the light behind you. Since the rules are to keep the light along side of you,
you'll need to turn slightly so that the light is once again by your shoulder. But yes, you're right - now you've moved off of your straight course. Keep doing this over and over and you will be moving in a circle around the artificial light. Shorten the distance of each circle and you will find yourself face to face with the soft glow of a Westinghouse.Scientists use this behavior to their advantage: it's one good way to collect insects that normally are hiding during the day. In many cases two kinds of lights are used: a mercury vapor or a black light (yes, same one your roommate used to light up the velvet poster of Jim Morrison). Hang one of these in front of a white sheet and the glow will be irresistible for the nighttime navigators.
A number of years ago when I was in graduate school at Georgia Southern University I was enrolled in an entomology class with the amazing Dr. Frank French. One of our assignments was to create an insect collection. A few days before the due date I found myself a bit short of the required number of specimens. Well, later that night I wandered over to the lights used to illuminate a billboard at the intersection of highways 301 and 25. Jackpot - there were literally layers upon layers of insects; living, dead, confused, preying on others - it was sweet madness. Needless to say thanks to the bright lights I finished my collection that night.
What's good for collectors is ultimately not good for the moths - not that the act of collecting itself is doing much of any harm but the prevalence of high-powered mercury vapor and sodium lights attracts moths away from the forests and shelter and into the mouths of birds who are up just before the sun shines. 
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