Finding a nest at night is a very difficult task for many different living things. The pure darkness of night without shelter can cause a great deal of danger. In an article by Nikk Ogasa titled “Some wasps’ nests glow green under ultraviolet light”, he explains how fluorescent wasp nests may help certain insects find their way home in the dim twilight by containing phosphors. The species that produce this special silk nest is called Polistes brunetus. He states that these glowing nests could be visible from up to 20 meters away.
The article provides a very important chemical process. The process of luminescence. A phosphor is a substance that exhibits luminescence; it emits light when exposed to radiant energy. When a phosphor is exposed to a form of radiation, the orbital electrons in the molecule are excited to a higher energy level. As the incoming radiation dwindles over time, they slowly return back to their base energy level. As the molecule returns back to its base energy level, the energy being released is in the form of light of a specific color. The image below shows this process.
The light comes from the silk fibers in the nest. In another article by Cara Giaimo, she states that “Bernd Schöllhorn, a chemistry professor at the University of Paris, was wielding his UV flashlight in the Cuc Phuong rainforest south of Hanoi when its beam landed on a paper wasp nest. It shone back so brightly, he said, that he thought another person had turned their own flashlight beam on him.” This shows the true power of the phosphors in the nest.
The chemicals that are involved in these phosphors have a major effect on the luminescence of the nests. Copper activated zinc sulfide and silver activated zinc sulfide are the two most known types of luminescence. Copper activated zinc sulfide emits green light at a wavelength of about 520nm to 530nm. The image below shows an intensity vs wavelength graph of Copper activated zinc sulfide.
It can be clearly seen that the peaks of almost all the curves fall into the 520nm to 530nm range. The color that is emitted at this wavelength can be directly compared to the fluorescent wasp nests that are created by the Polistes brunetus, this color is also known as the green “glow in the dark '' color that we all know very well.
The effects of these glow-in-the-dark homes are still being researched. The significance of having a glow-in-the-dark nest can have many possible advantages and even some disadvantages. In the coming years, deeper research will shed light on these aspects of glow-in-the-dark nests.
Sources:
Giaimo, Cara. “The Grooviest Cocoons in the Insect Kingdom.” The New York Times, The New York Times, 2 Sept. 2021, www.nytimes.com/2021/09/02/science/wasps-glowing-nests.html.
Ogasa, Nikk. “Some Wasps' Nests Glow Green under Ultraviolet Light.” Science News, 2 Sept. 2021, www.sciencenews.org/article/wasp-nests-glow-green-ultraviolet-light-fluorescence.
You have selected an interesting article. The title is effective. "Glow in the Dark" is always interesting. It is one of the things that young people find attractive about chemistry. The NY Times article has a couple of pictures of glowing nests. You might have included one of those (unless you had technical difficulties). Your explanation of luminescence is good. A key point is that uv excitation gives visible luminescence because some of the excitation energy is dissipated by non-radiative transitions (basically heating the phosphor and its matrix). That is the point of your energy level diagram. The information about the specific luminescent species is interesting. Also interesting are the questions around the purpose of this luminescence and the fact that many of these questions remain to be answered.
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