Lampyridae is a family of arthropoda, mandibulata, insecta, Pterygota, Coleoptera, polyphaga, and belongs to a family of Fluorescence, the other two families are Lycidae and Cantharidae. Fireflies are commonly known as "fireflies", and Cantonese are also called "fireflies". About 2,000 species are known worldwide and are distributed in tropical, subtropical and temperate regions. 54 species in 10 genera have been recorded in China. Common species: Chinese yellow fluorescent (Luciola chinensis L.), mountain window firefly, yellow edge firefly.
Insects of the family Fluoresceinidae are 4-18 mm long; flattened, multi-black, reddish-brown or brown; the head is hidden under the dorsal plate of the anterior thorax, with 11 antennae, filamentous, ctenomorphic, etc.; the compound eyes are developed; the dorsal plate of the forethia is mostly semi-circular; the basal segment of the anterior midfoot is conical, and the forefoot has subunit segments; the basal segments of the posterior foot are transverse, the tarsal segments are 5-5-5; the elytrapts are flat, the cover and ventral end, and the wing surface has multiple ridges; the abdomen can see 7-8 segments, the terminal 2 segments (male) or 1 segment (female), which has phosphine luminescence, and can glow yellow-green cold light by luminescent enzyme action; females are mostly missing wings. Adult insect lifespan is generally only 5 days to 2 weeks, luminescence is used to attract the opposite sex, luminous time is generally only maintained for 2 to 3 hours, different kinds of flash intervals are not the same. Adults and larvae are predatory and generally occur at water's edges and in warm, moist places. The other two families are daytime active and do not emit light.
Fireflies' eggs, larvae, pupae, and adults all emit light. The glow of firefly larvae is thought to have a warning and intimidating effect on predators, and adult insects are believed to use flashes of light for species identification, courtship and trapping. Usually, the male fireflies emit specific flashes of light during flight in the air, and the female fireflies send a response signal, which the male fireflies use to find and locate the female fireflies. Female fireflies are species-specific in duration and interval time, so species information, sex information, and location information can be provided to males. In the competition of males of the same firefly, the pressure of natural selection makes the courtship ritual of male fireflies before mating more and more complicated and lasts longer and longer. Female fireflies do not simply choose the male fireflies with the strongest flash brightness, and factors such as the size of the male individual, the speed of movement and the mating guard posture also determine the choice of female fireflies to male fireflies. When females of Photinus concimilis are competed by multiple males, they choose males whose flash frequencies are higher than average and whose flash time is close to the average. There is more research on the flash ac signal of fireflies abroad, while there is less research in China except in Taiwan.
Composition of the firefly flash signal
Light is used as a carrier of information, and the amount of information contained in it varies with the degree of modification of the photocarrier. The information contained in the flash signal, the transmission and reception of the flash signal are all factors that affect the communication between the sexes of the fireflies. The frequency, spectrum, intensity, and spatial distribution of the flash signal and the spatial distribution of these parameters can all be seen as the encoding of the signal. A single flash signal contains the following parameters: spectral composition, shape of the emitter, flash signal mode, and movement of light.
Illuminator
The shape and size of the luminaire is usually the basis for the identification of fireflies between species, and the morphology of different firefly luminaires varies greatly. Male fluorescent emitters are generally 2 segments, female fluorescent emitters 1 to 3 segments, the difference is larger, such as aquatic fireflies Luciola substriata male fluorescent emitter 2 sections, the 1st section of the luminescent is located in the 5th abdominal segment, band-like, the 2nd section of the luminescent is located in the 6th abdominal segment, in the shape of a "V", the female fireflies only have 1 luminous device, banded, located in the 5th abdominal segment. [3]
Spectral composition
The color of the light emitted by the firefly is determined by the structure of the fluorescein in its body and the way the fluorescein interacts with the luciferase, and the fluorescence spectrum is specific and the spectrum of different species of fireflies is different. Most fireflies emit yellow-green fluorescent light, and the information contained in the yellow-green light at night is easily received by the same kind of fireflies. In signal transmission, yellow-green light minimizes losses and thus improves the efficiency of signal reception, that is, the signal-to-noise ratio.
The movement of light
The movement of light has not yet been found to encode information, but 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, emit a kind of specific flash for courtship, and their luminous trajectory is species specific. Female fireflies do not identify species and sex according to the individual flash pulses of male fireflies, but identify the flash signal sequence and flash trajectory emitted by male fireflies when flying.
Flash signal pattern
Fireflies' flash patterns contain many sub-parameters, such as male-specific flash patterns, male-specific pattern intervals, female response delaytime, and female flash length. The flash signals of different fireflies are very different, and different behaviors of the same fireflies have different flash signals. The study found that only when the Photoinus pyralis male flash emitted a simulated response flash for 2s could the male fire be lured. Female fireflies of Photinus scintillans only respond to flashes with 0.13 to 0.16 s intervals, but not to flashes spaced 0.20 to 0.34 s.