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2023-03-18 13:19:39
The evolution of blood-sucking insects began at the beginning of the Triassic-Jurassic period. At that point, groups of flies and mosquitoes began to proliferate. During the Triassic, mosquitoes began to evolve into the domestic mosquito subfamily and the Anopheles subfamily, and during the Jurassic period, the Anopheles mosquito and the Aedes mosquito diverged. Besides, blood-sucking aphids also develop at this time.
There are two main theories about the evolution of blood-sucking insects: the herbivorous hypothesis, the carnivorous hypothesis.
Almost all of us have been bitten by a mosquito in our lifetime. They cause itching, discomfort, skin abrasions and, most dangerously, infectious diseases that can cause rapid death.
The hypothesis that eating plants corresponds to mosquitoes. Mosquitoes still initially ate plants, but starting in the Jurassic, with the emergence and evolution of angiosperms, a terrestrial revolution began and warm-blooded mammals, dinosaurs, and birds appeared. presently. Some species of mosquitoes, after inadvertently receiving blood nourishment, begin to turn to blood-sucking.
It is generally accepted that blood parasites in arthropods increased at least sixfold during the Jurassic and Cretaceous periods. They suck blood through suckers – organs originally born to suck tree sap; This needle-like jaw is also an effective tool for mosquitoes to adapt to eating blood.
Each year, mosquito bites are responsible for the deaths of about 1 million people worldwide. More people die from mosquito bites than people in big cities like Detroit or Geneva. Many people survive, but still suffer from serious sequelae that stay with them for the rest of their lives.
During the Mesozoic, insects began to approach vertebrates, either because they ate the fruit and young leaves of trees at the same time as these species, or the insects were attracted to the fruit and seeds contained in the nest. of vertebrates.
This allows the insect to inadvertently come into contact with and feed on blood draining from the wound, and then evolve to intentionally open the wound; Over time, the insect’s mouthparts continue to grow, allowing the insect to remove scales from the wound, opening the old wound and, as a result, the ability to penetrate the skin and make it difficult for these wounds to heal. more blood.
It is clear that vertebrate blood has a higher nutritional value and is easier to digest than plant sap, as evidenced by the fact that blood-sucking Aedes mosquitoes are more likely to develop and reproduce than sap-sucking mosquitoes.
Mosquitoes are the most dangerous animals in the world. A single mosquito can infect more than 100 different victims.
The transition from eating tree sap to drinking blood persists in modern times. The prime example is the Spodoptera moth, a species of the family Noctuididae with an improved sharp beak. This beak is used by most nocturnal species to pierce the outer skin of fruit, but the moth Spodoptera uses it to puncture the skin of vertebrates to suck blood.
The Spodoptera moth has a body length of about 20-25mm, a wingspan of 35-45mm. This moth can live an average of 1-2 weeks depending on food conditions. On average, a female butterfly can lay 300 eggs, but if conditions are right, they can lay 900-2000 eggs.
The caustic hypothesis corresponds to other insects that do not have specialized sucking organs. These insects cannot feed on blood directly, but develop into indirect blood-sucking insects through long-term coexistence with vertebrates.
Vertebral nests attract insects perhaps because the warm, humid environment is so conducive to the vast majority of insects. Furthermore, the abundance of food in a vertebrate’s nest may also be the reason it attracts insects.
Psocoptera is an order of insects, They first appeared in the Permian period about 295–248 million years ago. They are considered the most primitive of the paraneoptera group. Their name comes from the Greek , psokos meaning gnawed or rubbed and , ptera meaning wing.
Initially, insects feed on faeces and fungi and inadvertently ingest organic debris such as skin debris or feathers in the nest. Over time, this has led to the development of the ability to digest organic debris, and they also feed directly from the host’s body.
Simultaneous morphological and behavioral adaptations allow insects to develop distinctive mouth muscles. Although these muscles are not used as a mosquito’s sucker, it can be used to penetrate the dermis to feed on the host’s blood. The evolution from caustic to bloodsucking was first discovered in members of the avian subspecies.
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