Insects

Insecta

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta

Pronunciation

How to pronounce Insecta: /ɪnˈsɛktə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Alciphanes clavata by the Smithsonian. Used under a CC0 license.

Perilampus muesebecki by the Smithsonian. Used under a CC0 license.

Diabrotica neoallardi by the Smithsonian. Used under a CC0 license.

Neocrepidodera konstantinovi by the Smithsonian. Used under a CC0 license.

Epyris coriaceus by the Smithsonian. Used under a CC0 license.

Isosoma albomaculatum by the Smithsonian. Used under a CC0 license.

Summary

Insects, belonging to the class Insecta, are the largest and most diverse group of animals, characterized by their three-part body structure, compound eyes, and varying life cycles involving metamorphosis. They serve vital ecological functions but face threats from human activities.

Physical Characteristics

Insects have a chitinous exoskeleton, a three-part body consisting of a head, thorax, and abdomen, three pairs of jointed legs, compound eyes, and a pair of antennae.

Identification Tips

Adult insects can be identified by their three-part body plan, with head, thorax, and abdomen. They typically have three pairs of legs on the thorax and may have one or two pairs of wings.

Habitat

Insects are found in a wide variety of habitats including snow, freshwater, tropical regions, deserts, and even the sea.

Distribution

Insects occur in every continent and almost all terrestrial habitats, with higher diversity in tropical rainforests.

Diet

Most insects are herbivorous, consuming plant material, although many are predators of other insects, some are parasitic, and others feed on decaying material.

Life Cycle

Insects undergo either incomplete (hemimetabolous) or complete (holometabolous) metamorphosis. Incomplete metamorphosis involves multiple molts where immature stages (nymphs) resemble adults, whereas complete metamorphosis involves four distinct stages: egg, larva (or caterpillar), pupa, and adult.

Reproduction

Most insects reproduce sexually through egg-laying, but some species can reproduce asexually and have unique reproductive strategies such as haplodiploidy and parthenogenesis.

Predators

Many insects have natural predators including birds, spiders, amphibians, and other insects.

Conservation Status

Human activities are causing significant declines in insect biodiversity, with many species at risk of extinction.

Ecosystem Role

Insects play critical roles in ecosystems such as pollination, decomposition, soil aeration, and serving as food sources for other animals.

Economic Impact

Insects affect agriculture as pests damaging crops, but also provide economic benefits through pollination, honey production, and silk.

Cultural Significance

Insects hold cultural and religious significance in various cultures, e.g., scarab beetles in ancient Egypt.

Health Concerns

Some insects are vectors for diseases and pests affecting humans and livestock.

Evolution

Insects are believed to have first appeared over 400 million years ago, with significant diversification events corresponding to climatic and ecological changes.

Similar Taxa

Misconceptions

In common parlance, insects are often mistakenly referred to as 'bugs', while 'true bugs' refers specifically to members of the order Hemiptera.