Sichuan online reporter Wang Daiqiang
Recently, when Zhao Li, director of the Chengdu Huaxi Entomological Museum, sorted out the specimens, he found that among the dragonfly specimens collected by the museum from the Jinkouhe area of Leshan, Sichuan in August this year, there was the world's smallest dragonfly species, the pygmy red dragonfly, which was the first time that this species was recorded in Sichuan. What's more, this batch of specimens contains the smallest dragonfly individual on record in the world, with a body length of less than 15 mm.
Zhao Li said that the pygmaea is recognized as the world's smallest dragonfly species, mainly distributed in Southeast Asia and southern China, and is the "dwarf" among dragonflies. According to the "Chinese Dragonfly Great Atlas" and academic materials published in Japan, South Korea, Taiwan and other places. They are 17–19 mm long, with the average male being 18.5 mm long and females 17.5 mm. Of the more than 10 individuals collected by the Huaxi Entomological Museum this time, the average male is only 16.5 mm in length, the female is 16 mm, and the smallest male is less than 15 mm. Significantly lower than other regional species population types.
Zhao Li analyzed that this population of pygmy red dragonfly is currently known to be the northernmost distribution record of the species in China, and may be a separately evolved population. Due to the special geographical environment of the Jinkouhe area in Leshan, Sichuan, where it was found, it belongs to the alpine canyon landform, and the highest mountain ranges on both sides of the canyon are more than 3,000 meters above sea level, but in the bottom area of the canyon at an altitude of 500-800 meters, there is an islandic tropical environment, so that this dragonfly, which was originally mainly distributed in southeast Asia and the tropical region of southern China, can breed here. However, due to the isolation of the high mountains, this population cannot communicate with other regional populations, so it evolved independently, resulting in a different size from the pygmy red dragonfly in other regions.
Zhao Li introduced that there are more than 5,000 kinds of dragonflies found in the world, and as of September 2020, more than 990 kinds of dragonflies have been found in China, more than 100 kinds more than the second place Brazil, which is a veritable country with the most dragonflies in the world. Due to its small size and the veins on its wings are simpler than those of other dragonflies, the dwarf red dragonfly looks like the "miniature simplified version" of the dragonfly we usually see. According to Zhao Li's observations, they have poor flight ability and can generally only move within a few square meters, but its male body is red, so it is still easy to find in the green plants. This dragonfly male is territorial, generally occupying a piece of water of about one square meter, staying there, even if disturbed, it will only fly to a place two or three meters away, and then after a while it will return to its original location. This dragonfly is different from male to female, the male is bright red throughout, the female is yellow-brown, and there are two columns of white spots on the sides of the chest and abdomen. They have transparent wings, a yellowish-brown base, and a golden sheen in the sun, which is very beautiful. Compared with other dragonflies, which tend to be as long as tens of minutes or even hours of tailing time, their tailing time is not long, only about 2 minutes. After mating, the female takes a break and lays eggs in water nearby. The time for the youngest to climb from the water to the grass to prepare for feathering is also very short, about 20 minutes to begin feathering, and within a few minutes to complete, while other dragonflies generally crawl out of the water to complete the feathering process takes several hours.
This dragonfly prefers a clean water environment, their presence can be used as an indicator of the environment, due to the development and construction of many areas, the distribution area of this dragonfly has become smaller and smaller.
The largest known species of dragonflies in the world is the helicopter bean girl megaloprepus caerulatus in Places such as Brazil, whose wings can spread up to 19.1 cm and its body length can reach about 12 cm. However, if you compare it purely by body length, another lucretia giant bean girl mecistogaster lucretia, the body length can reach 15.5 cm. The largest known dragonfly in China is the butterfly cleft-lipped dragonfly Chlorogomphus papilio, with a maximum wingspan of 15.6 cm and a body length of up to 9 cm. In addition, the giant veined dragonfly that lived in the Carboniferous period could reach 75 cm in wingspan, but the species was already extinct.
The picture was taken by Zhao Li