Answered by Alana Jensen, Environmental Educator, ESER Program
You’ve probably noticed that whenever the weather starts to turn cold, you see more insects crawling around your home. The reason for this is that the colder weather drives insects to seek refuge in a warm and dry place, like the conditions your home provides. They get into our homes by squeezing through tiny openings in our home’s foundation and spend the winter hibernating in attics, soffits, wall voids and window and door casings, and then they enter a diapause or dormant state. Diapause is a state in which their growth, development, and activities are suspended temporarily, with a metabolic rate that is high enough to keep them alive. In comparison, vertebrates undergo hibernation, during which they have minor activity and add tissues to their bodies.
Usually it’s the adult insects that we see in the wintertime in our homes. These insects, including wasps, flies and beetles, spend the winter in their adult stage. Other insects, like moths, may spend the winter in their pupa stage. Insects, like Praying Mantis or grasshoppers, spend the winter in the egg stage. Still others, like many butterflies, spend the winter as a larva, becoming dormant in a safe place.
With the onset of warmer weather, the insects that used our homes to stay warm during the winter begin to emerge from their hiding places beneath baseboards, behind window and door frames, and around light fixtures and ventilators. As they attempt to escape to their natural habitat outdoors, some inadvertently make their way into the living areas of the home and since some insects are attracted to light, they typically head toward the nearest window.
Phototaxis is the way the living organisms react to the light. It can be positive (moth flying toward the light) or negative (cockroach hiding in the darkness). Do you think that the color of the light might make in difference in an insect’s attraction to a light source? Let’s do an experiment to find out.
Materials: Four small lamps, four different colored light bulbs of the same wattage (red, green, blue, and white), flypaper
- Place the four lamps outside in an area that doesn’t receive a strong light source from another light. Put the lamps at least 15 feet apart from each other.
- Insert a different color of light bulb in each lamp. Remove the lamp shades if there are any.
- Put a piece of flypaper near each lamp. The flypaper should be an equal distance from each lamp and in the same relative place.
- When it is dark, turn on the four lamps. After 15 minutes, count the number of insects captured on each piece of flypaper. If you didn’t get many bug captures, you can increase the time.
- Repeat the experiment twice more, recording your data for each time period. Which color appears to be the most “attractive” for insects?