2. Dragonflies: They can prey on mosquitoes, flies and other harmful insects, and some can prey on butterflies, moths, bees and so on. In fact, they are all beneficial insects.
3. Mantis: a carnivorous insect, all small species of insects can be preyed by mantis, especially the eggs, larvae, naked pupae and adults of flies, mosquitoes, moths and butterflies are suitable prey.
4. Chrysopa: It is a polyphagous insect, preying on a variety of soft insects and mites, honeydew discharged by insect eaters, nectar and pollen secretion of plants, etc.
5. Ladybugs: mainly feed on aphids, while ladybugs and ladybugs prey on aphids, scale insects, whiteflies and tetranychus. Ladybug septempunctata is a common natural enemy of aphids in Palaearctic, and it is used to control cotton aphids in China by migration and protection.
Extended data:
1, pests and beneficial insects are relative, beneficial insects will do harmful things to human beings, and pests will do beneficial things, but to different degrees. Some pests have high nutritional value and can be eaten by human beings or become medicinal materials for treating certain diseases.
2. The visual nerve of most pests is particularly sensitive to ultraviolet with wavelength of 330-400 nm, which has strong phototaxis and can trap and kill many pests efficiently.
3. From the ecological point of view, many insects, birds, amphibians, etc. It preys on pests, so it is defined by humans as beneficial insects or beneficial animals or beneficial birds. If there were no pests in nature, there would be no beneficial insects, birds and animals that preyed on them.
4. Many insects are considered beneficial because they prey on or parasitize other insects that destroy crops and store products, and the most important beneficial insects are parasitic insects.
References:
Baidu encyclopedia _ beneficial insects Baidu encyclopedia _ pests