Insects can be creepy, crawly, frightening, but fun. Finding facts about something appearing to be dangerous is a good way to find the proof about whether it is deadly or useful. Most insects are harmless, and necessary for the well-being of the earth and environment.
In general, insects are cold bloodied creatures, so growth is dependent on climate. Hot weather encourages growth, while cold weather hinders it. All insects except spiders have three body parts, six jointed legs, a life cycle of different degrees of growth, two antennae, an exoskeleton, and wings.
Insect Anatomy
The head, thorax, and abdomen are the insect’s three body parts. Insects see, smell, eat, and feel with their heads. The head consists of the eyes, antenna, and mouth. Insects have one of two types of eyes: simple eyes have one lens, and compound eyes have many lenses for seeing. The antennae are sometimes called feelers and it is good explanation of what they do; the insect uses the antennae to feel, hear, smell, and hunt food.
There are four types of insect mouths, and they are divided into two categories depending on how the insect uses them to eat. Mouths can chew, poke, suck, or sponge, but most mouths are used for chewing or sucking.
The abdomen is used for digestion, like a stomach, and for reproduction, which means creating babies. This is the largest body part, and contains breathing holes, called spiracles, through which the insect breathes.
Insects have an exoskeleton - imagine your skeleton outside your body - to help you picture the exoskeleton and its purpose. This hard exterior helps to protect the insects from danger.
- Kinds of Insects
- Insect Mouthparts
- Insect Anatomy
- Insect Guide
Insect Reproduction
There are male and female insects, just like humans are men or women. The male has a sex organ called the testes which contain sperm, while the females have ovaries which contain eggs. Most insects reproduce by mating; the male transfers his sperm to the female’s egg and fertilizes it. Some insects can reproduce without the male fertilizing the egg, and that is called parthenogenesis or asexual reproduction. The fertilized eggs can be deposited outside the mother’s body to mature, but in some species the female keeps the eggs inside her body until they hatch.
The mother lays the eggs using a body part called the ovipositor - picture the bee’s stinger. It can sting for defense, but it is also the pathway for the eggs to leave the insect body. The time needed for the eggs to hatch depends upon the type of insect.
- How Insects Reproduce
- Insects Sexual Reproduction
- How Beetles Reproduce
Metamorphosis
Metamorphosis is the term used to describe the different stages of growth insects experience as they become adults. All insects start from eggs, and when hatched enter the larval or pupa stage. During this time, the insect grows and sheds its skin several times. As it grows, the old skin becomes too small, and it must molt, or shed, the skin so it can become an adult. The final part of the life cycle is when the insect becomes an adult.
In gradual metamorphosis, the larva look very similar to the adult insect. They may not have wings, but they will eat the same food and behave just like the adults. In gradual metamorphosis, insects move through only three stages of the life cycle: egg, larval, and adult.
In complete metamorphosis, the larva do not look like the adults, nor do they feed or behave like them. These insects will go through a four-step growth process: egg, larval, pupa, and adult. Growth continues in the pupa stage, and some insects form a cocoon for protection during this period of growth. In fact, you might not even recognize them as being the same species, but when the transformation is complete, they will resemble the adults.
- Metamorphosis Life Cycle
- Stages of Metamorphosis
- Insect Metamorphosis
- Butterfly Metamorphosis
Insect Classification and Identification
Scientists and other researchers classify insects to help them learn more about each species, and understand their similarities. They study the eating patterns, life cycles, and other common features of each insect family. By doing this, they can identify helpful insects, like bees and butterflies, and distinguish them from harmful insects, like poisonous spiders.
- Insect Classification at the Insect Zoo
- Catch and Release Insect Identification
- Insect Image Gallery
Written by Michael S. Atwood