Why do fireflies glow?

Fireflies get their name because their tails can emit fluorescence. Adults use species-specific flash signals to locate and attract members of the opposite sex, thus accomplishing the mission of courtship, mating and reproduction. A small number of fireflies use flash signals to prey. Another function is to serve as a warning signal. Let's take a look at why fireflies glow.

Why do fireflies glow?

Fireflies have special luminous cells, in which there are two kinds of chemicals, one is called luciferin, the other is called luciferase. Luciferin can consume ATP and react with oxygen under the catalysis of luciferase. The excited state of oxidized luciferin is produced and photons are released when the oxidized luciferin returns to the ground state from the excited state. Almost all of the energy released in the reaction is released in the form of light, only a very small part is released in the form of heat, and the reaction efficiency is 95%. As a result, fireflies do not burn excessively. So far, humans have not been able to produce such an efficient light source.

In what season do fireflies have?

Fireflies usually appear on rivers, pools and farmland in summer, and the range of activities does not leave the pure water source. The time of activity of adults varies according to their species. There are diurnal and nocturnal species of adults during the day and night, and the time of occurrence of nocturnal activities is from 18:00 to 3am. Generally speaking, most species start their activities after sunset, and most of them stop at 20: 00 p.m.

Firefly flash signal composition

1. Luminous organs: the shape and size of luminous organs are usually the basis for interspecific identification of fireflies. The shapes of luminous organs of different fireflies are very different. The luminous organs of males and females are generally 2 and 3, respectively. For example, the luminous organs of aquatic fireflies are located in the 5th ventral segment, the 1st section is located in the 5th ventral segment, the 2nd section is located in the 6th ventral segment, and the female has only one section. It is located in the fifth abdominal segment.

2. spectral composition: the color of light emitted by fireflies is determined by the structure of luciferin and the interaction between luciferin and luciferase, which is species specific, and the spectra of different species of fireflies are different. Most fireflies emit yellow-green fluorescence, and the information contained in the yellow-green light at night is easily received by the same kind of firefly. In signal transmission, yellow-green light can reduce the loss as much as possible so as to improve the efficiency of signal reception, that is, signal-to-noise ratio.

3. The movement of light: in non-bioluminescent animals, whether vertebrates or invertebrates, posture is the most important and direct visual signal in behavioral contact. Male fireflies usually fly in the air, emitting species-specific flashes for courtship, and their luminous trajectories are species-specific. The female firefly does not identify the species and sex according to the single flash pulse of the male firefly, but identifies the flashing signal sequence and flashing track emitted by the male firefly during flight.

4. Signal mode: the flash mode of fireflies contains many sub-parameters, such as male-specific flash mode, male-specific flash interval, female response time and female flash time. The flash signals of different fireflies are very different. Different behaviors of the same firefly have different flash signals. It is found that only when the male firefly flashes for 2 seconds, can the male fireflies be attracted.