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Why are there so many flying insects in summer? Yellow and green clothes attract insects most comprehensive report: this kind of small flying insect is aphid. They like to chase yellow clothes because they have a positive tendency to yellow. They like to stick to the fibers of clothes. That kind of insect has a short life and will die soon if it can't move. Clothes from the temperature and humidity are not suitable for aphids to survive, not to mention without his food, he died

According to the positive tendency of aphids to yellow and negative tendency to silver gray, yellow board was used to lure aphids or silver gray film was used to avoid aphids.

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What is taxis

Taxis is a kind of directional activity to some stimulus. There are many kinds of irritants, such as heat, light, chemical substances and so on. Therefore, there are thermotaxis, phototaxis and chemotaxis. Since there are two kinds of responses to stimuli: the tendency and the back, the tendency can be divided into positive tendency and negative tendency (that is, the back).

It is necessary for insects to respond to stimuli. Taxis is a way of responding. For example, the exoparasitic insects (fleas, lice) of higher animals need the temperature of the animals as a stimulus to find the host animals by their thermotaxis. Many insects have obvious response to light. Most nocturnal moths have phototaxis; cockroaches, for example, often hide in dark places and hide when they see light, which means they have negative phototaxis (or backlighting). Chemotaxis plays an important role in searching for food, heterosexual mating and oviposition sites.

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Of course, there can be other taxis, such as geotaxis, hygroscopicity, sonotaxis and so on.

No matter what kind of taxis, they are always relative and have a certain degree of selectivity to the intensity or concentration of stimulation. The most suitable temperature for ectoparasitic insects is the temperature of the host animal. Human body lice often live on people's close clothes. If a person has a fever due to illness, that is, the body temperature exceeds normal, the body lice will crawl away from the human body, showing negative thermotaxis. This is one way lice spread infectious diseases. When insects encounter several kinds of temperature at the same time, they always move to the most suitable temperature and avoid the unsuitable temperature. Phototactic insects also have a choice of light wavelength and light intensity. The aphid did not take off at night, but took off during the day, and the light had a certain guiding effect on its migration; but when the light intensity reached more than 10000 m candlelight, Myzus persicae did not take off. Moths have phototaxis at night, but they hide in the daytime when the light is too strong. Photo 1 shows the moths flying to the white cloth under the lamp after being lured by the lamp at night. The same is true for chemical stimuli. In the experiment of sex attraction, it was proved that the high concentration of sex attractant not only failed to attract, but also became an inhibitor.