Question

Общая характеристика насекомых

Answer 1

Класс Insecta (насекомые) - крупнейший среди типа членистоногих. Насекомые присутствуют во всехэкологических нишах, за важным исключением - морей

Класс насекомых включает всех трахейнодышащих членистоногих, обладающих тремя парами ног. Тело их отчетливо подразделяется на голову, грудь и брюшко. Большинству представителей класса присуща способность к полету - единственная в этом смысле группа среди всех беспозвоночных.

. В большинстве своем - это весьма активные животные, а потому развили целый ряд чрезвычайно тонко организованных органов чувств. Из-за того, что насекомые покрыты твердым хитиновым наружным скелетом (кутикулой), их органы чувств, главным образом, основываются на кутикулярных сенсиллах.

Класс насекомых богаче всех прочих классов по числу представителей. На долю Insecta приходится около 70% общего числа известных видов животных. По разным источникам число изученных видов насекомых колеблется от 600000 до 1 500000. Тем не менее и до сих пор в научной литературе ежегодно описываются новые формы. Если принять во внимание, что многие виды насекомых встречаются в громадном количестве особей, то становится понятным, какую огромную роль насекомые играют в наземных биоценозах. Естественно, что и практическое значение насекомых чрезвычайно велико.

Answer 2

General Characteristics of Insects

Insects are a diverse group of animals that belong to the class Insecta. They are the most abundant and diverse group of animals on Earth, with over a million known species and many more yet to be discovered. Insects can be found in almost every habitat, from the deepest oceans to the highest mountains and from the tropics to the polar regions.

Body Structure: Insects have a characteristic body structure consisting of three main parts: the head, thorax, and abdomen. The head contains the sensory organs, including the eyes, antennae, and mouthparts. The thorax is the middle part of the body and is divided into three segments, each bearing a pair of legs. Insects also have wings attached to the thorax, although not all insects can fly. The abdomen is the posterior part of the body and contains the digestive, reproductive, and respiratory organs.

Exoskeleton: Insects have an exoskeleton, which is a hard, protective outer covering made of a substance called chitin. The exoskeleton provides support and protection for the insect's body and also serves as a barrier against water loss. However, because the exoskeleton does not grow, insects must molt or shed their old exoskeleton in order to grow larger.

Metamorphosis: Many insects undergo metamorphosis, which is a process of transformation from one form to another. There are two main types of metamorphosis: incomplete metamorphosis and complete metamorphosis. In incomplete metamorphosis, the insect goes through three stages: egg, nymph, and adult. The nymph looks like a miniature version of the adult but lacks wings. In complete metamorphosis, the insect goes through four stages: egg, larva, pupa, and adult. The larva, also known as a caterpillar or grub, looks very different from the adult and often has a specialized feeding structure.

Feeding and Reproduction: Insects have a wide range of feeding habits. Some insects are herbivores and feed on plants, while others are carnivores and feed on other insects or small animals. There are also insects that are scavengers, feeding on decaying organic matter, and insects that are parasites, feeding on the blood or tissues of other animals. In terms of reproduction, most insects lay eggs, although some give live birth. Insects have a variety of reproductive strategies, including sexual reproduction and asexual reproduction.

Ecological Importance: Insects play a crucial role in ecosystems. They are important pollinators, helping to fertilize plants by transferring pollen from the male reproductive organs to the female reproductive organs. Insects also serve as a food source for many other animals, including birds, reptiles, and mammals. Additionally, insects are important decomposers, breaking down dead plant and animal matter and recycling nutrients back into the ecosystem.

Economic Impact: Insects have both positive and negative impacts on human society. Some insects are beneficial as pollinators, natural pest controllers, and producers of valuable products such as honey and silk. However, some insects are pests that can damage crops, spread diseases, and cause economic losses. Controlling insect pests is an important aspect of agriculture and public health.

In conclusion, insects are a diverse group of animals with a wide range of characteristics and ecological roles. They are incredibly abundant and play important roles in ecosystems and human society.