Spring is here, and many animals are on the road to migration. We are familiar with the migration of birds. “Little swallows, wearing floral clothes, coming here every spring…” This song succinctly sums up the migration of Jiayan.
In fact, it is not only birds that migrate in nature, but also mammals, reptiles, fish and so on. But the migration of one type of animal is often overlooked, that is, insects.
In the eyes of ordinary people, insects are only weak, even if they are migratory, it is difficult to set off a big wave. But is this really the case?
What is the migration amount of insects?
Dr. Hu Gao from Nanjing Agricultural University and scientists at the Lausanne Test Station in the United Kingdom monitored the migration of insects from 2000 to 2009. They found that the migration of insects has a large seasonal variation – a large number of insects in the spring North migration, moving south in the fall.
These seemingly inconspicuous insects can erupt amazing energy on the way of migration. Their migration can not only complete the inheritance of their own lives, but also affect the entire ecosystem, just as “Asian butterfly pats its wings, a few months after the Americas There will be a tornado (the butterfly effect).
In recent years, scientists have found that the migration of insects is staggering. In England alone, the annual migration of insects can reach an astonishing 3.5 trillion times, and the combined weight can reach 3,200 tons, which is equivalent to the displacement of a small destroyer. Such large biomass is not a small number in the entire ecosystem, and they have far-reaching effects.
For insect-feeding predators in the ecosystem, this is a big meal; in turn these insects can also affect plant growth. Therefore, the migration of insects is not only their own, but also affects predators, prey and competitors.
In addition, these insects are a huge source of energy and nutrients, and may carry a large number of pathogens for metastasis, with unusual effects on species circulation and energy flow throughout the ecosystem.
Swarm of locusts
The migration of most insects is a phenomenon in nature and will not bring turmoil to human society, but the locusts are different. In 2016, the Russian government once declared a state of emergency because it suffered the most serious locust disaster in 30 years.
The locusts flying through the sky passed through southern Russia. For a time, the sun and the moon were dull, and the sky was dark, like the end of the world. According to reports, more than 10% of the farmland in Russia was destroyed by the disaster, and the affected area was as high as 70,000 hectares.
This is actually a large migration of locusts, but their number is too large. According to scientific investigation, these locusts are from distant North Africa.
Monarch Butterfly Migration
The most beautiful migration on earth
In addition to the annoying locusts, there are also monarch butterflies in the migratory army of insects, and their migration is shocking. The Monarch Butterfly wingspan is about 10 cm and weighs 0.5 grams, but they have staged the legend of the way of migration with weak life.
Spring has come, and everything has recovered. In the forests of southern Mexico, the eggs of a monarch butterfly hatch larvae. The larvae continue to suck the leaves, and when they grow up, they become cockroaches. After that, they began to embark on the road of migration, all the way north. On the way to migration, they continue to breed, and the descendants of breeding continue to embark on the road of migration.
The first generation of monarch butterflies began in early spring, and the third generation of monarch butterflies reached the end of the migration at the end of the summer – in Canada. After arriving, they did not dare to stop and quickly prospered the next generation. When the fourth generation of the emperor butterfly was born, it was already in crisis, and they must move to Mexico for the winter.
The fourth generation will have to complete the migration path of the first three generations of emperor butterflies alone, which means that the fourth generation of emperor butterflies will fly about 4,000 kilometers in the next two months to reach the southern part of Mexico for wintering, which is equivalent to an average daily. Want to fly 60 to 70 kilometers! In order to ensure the ability to reach the wintering ground, the fourth generation of the king butterfly has a life span of 9 months, which is three times the life of the first three generations. The four generations of the monarch butterfly have a reincarnation. Each generation has a mission of each generation. The first three generations desperately reproduce and expand the population. After the fourth generation, they have gone through many hardships and brought the ethnic group back to the south.
How do the king butterflies navigate during long-distance migration? Originally, the monarch butterfly relied on the sun to navigate. They contained a biological clock in their body. Two tentacles could generate a clock signal to correct the sun’s orientation. Under the guidance of the sun, they all flew southwest, flew forward along the right side of the sun in the morning, and flew to the left of the sun in the afternoon.
However, relying solely on the sun for navigation can only find the general direction, but not enough to return to the place where the ancestors lived. There should be other auxiliary mechanisms.
The magnetic induction protein and the photosensitive crypto-pigment protein complex in the monarch butterfly can spontaneously align with the external magnetic field, so that the animal can accurately sense the direction and intensity of the magnetic field. In addition, the smell may also be involved in the navigation of the Monarch Butterfly.