CATDOLL : CATDOLL: Which of locusts, aphids, frogs, mantises, seven-spotted moths, red spiders, dragonflies, and geckos are beneficial insects and which are pests? How are they classified?

1. Among locusts, aphids, frogs, mantises, seven-spotted spiders, red spiders, dragonflies, and geckos, which ones are beneficial insects and which ones are pests? How are they classified?

Pests Locusts, aphids, spider mites

Beneficial insects: frogs, mantises, seven-spotted moths, dragonflies, geckos

2. Locusts are agricultural pests. When they harm crops, they are in the following stages of development:

C Nymph and adult stages

3. Locusts are agricultural pests that harm many grass plants. They have piercing-sucking mouthparts. ______ (True or False)

Chewing mouthparts, its nutrition method is to chew the solid tissue of plants or animals for food, such as locusts;

Piercing-sucking mouthparts, which are formed into a needle-shaped tube and used to suck the juice from plants or animals. This type of mouthparts cannot eat solid food, but can only penetrate into tissues to suck juice. For example, mosquitoes;

The siphon mouthparts are formed by the outer leaves of the mandibles clasping together to form a long tubular food passage, which is coiled at the front and lower part of the head, like the spring of a clock, and stretches when in use. Such as moths and butterflies;

The main parts of the licking-sucking mouthparts are the head and the kiss mainly composed of the lower lip. The end of the kiss is the lip composed of the pseudo-trachea formed by the lower lip, which is used to collect liquid on the surface of objects; the lower lip covers the upper lip and tongue, which form the food tract. There is also a saliva duct in the tongue. Such as flies.

So the answer is: ×

4. Why do humans define locusts as pests? Do locusts become pests only because they affect human development?

Hi, this is the selfish side of human beings. Those that are beneficial to human beings are beneficial insects, and those that are harmful to human beings are pests. All angles are evaluated from the perspective of human interests, not from the perspective of nature.

5. Why are locusts considered the most harmful pests?

In recent years, many parts of the world have experienced serious locust plagues. In 1979, pastures and farmlands in 14 states west of the Missouri River in the United States were covered by dense swarms of hungry locusts. In places such as Yakima in Washington State, locusts covered the roads, and the thickness of the locusts was enough to pose a danger to moving vehicles.

The largest locust swarm in history was recorded in 1889, when it appeared over the Red Sea. It was estimated to be 250 billion locusts, weighing 550,000 tons. When flying, the sound was so loud that it covered the sky and the sun was eclipsed. It was also called a "wonderful sight".

Locusts have amazing flying abilities. They can fly for three consecutive days. Locusts will not drown immediately after falling into the water. Adult locusts can swim in the water for more than 24 hours. Even mountains and rivers cannot stop their movements. So they are the most harmful pests.