[Cultivation Program] In the hot summer, insects have a "cool way" to escape the heat

Author: Lao Ke’s Brain Studio

Withered vines, old trees, crows, fish and shrimp for dinner, air conditioning, wifi, and watermelon. In the hot summer, cicadas chirp, people use air conditioning and eat watermelons to avoid the suffocating heat. The honest and simple buffalo soaks its bulky body in the pond to resist the scorching heat. The cunning loach buries its body in the mud and goes into hibernation without eating or drinking. So, how do small insects cope with the hot summer in the wild under the sun?

If you observe carefully, you will find that insects often "accidentally" fall to the ground from the grass.

Are they fainted by the heat?

Copyright image, no reproduction is authorized

the truth

The truth is, they did not fall to the ground due to fainting from the heat, but chose to fall to the ground on their own initiative. This is actually one of their ways to avoid the heat.

Thermoregulation

According to scientists’ statistics, so far, no insect has been found to regulate its body temperature by sweating like humans or mammals. Insects are very small, and they do not have feathers and hair like birds and mammals. Their special heat-insulating and heat-insulating structures make it easy for them to dissipate heat and lower their body temperature. At the same time, they are also easy to accept external heat and increase their body temperature. Therefore, as cold-blooded animals, the body temperature of insects mainly changes with the changes in the external temperature. The body temperature is low when the temperature is low, and the body temperature is high when the temperature is high. In the exposed wild, insects choose to fall to the ground in order to find a cooler and more humid place to cool themselves down. This heat-avoiding behavior can increase the insects’ own chances of survival, but this behavior often consumes energy and affects the feeding of piercing-sucking insects, leading to delayed development and reduced reproduction.

Copyright image, no reproduction is authorized

Heat acclimation

Insects living in nature naturally have a certain degree of adaptability. As long as they are not suddenly exposed to extremely high temperatures, they will adapt to changes in environmental temperature through adaptive domestication.

For example, if we put an insect at 22 degrees directly into 38 degrees, it may die in 40 minutes. But if we put this insect at 22 degrees into 34 degrees for half an hour and then into 38 degrees, it may not die after two hours. It gradually undergoes an adaptive domestication process, and improves its resistance and tolerance to extreme high temperatures by undergoing heat domestication at non-lethal temperatures.

Copyright image, no reproduction is authorized

Rapid evolution

Darwin's theory of natural selection holds that "survival of the fittest" is the rule of nature. Climate warming makes heat-resistant insects more likely to survive. Most insects that reproduce and develop quickly will improve the average heat resistance of the entire species through "survival of the fittest", that is, through evolutionary adaptation to ensure survival, especially for species that are particularly small, reproduce a lot, and develop very quickly, and many generations can occur in a year.

Aphids belong to this category of insects. There are three main types of wheat aphids in my country: Macrosiphum avenae, Schizaphis graminei, and Aphis graminei. In the past, Macrosiphum avenae and Schizaphis graminei were the aphids that harmed wheat the most. Among them, Macrosiphum avenae mainly ate wheat grains after filling, causing particularly large yield losses. In recent years, scientists have found that under the influence of climate warming, there are fewer and fewer Macrosiphum avenae with poor tolerance to high temperatures, while there are more and more Aphis graminei, which are more heat-resistant. Aphis graminei has a slightly black body color and mainly eats the roots and stems of wheat, which has a greater impact on crops in the seedling stage.

Copyright image, no reproduction is authorized

Use your own developmental stage differences to mitigate the threat of high temperatures

As we all know, eggs, larvae, pupae and adults belong to different developmental stages of insects, which we also call different insect stages. Their heat resistance is different, and different insect stages often overlap and exist at the same time in nature.

Copyright image, no reproduction is authorized

High temperatures will kill insects that are not heat-resistant, while heat-resistant insects will survive. After a few days, when the high temperature passes, the heat-resistant insects will continue to develop, develop into adults and reproduce, and the entire species can be preserved. Therefore, insects with overlapping generations can use the differences in heat resistance during this development process to avoid the population being wiped out under extreme high temperatures.

This article is produced by Science Popularization China-Starry Sky Cultivation Program. Please indicate the source when reprinting