The head is the anterior of the three body
regions of an insect. It bears the eyes (usually
Head a pair of compound eyes), the antenna and the
The thorax is the middle of the three body
regions of an insect. It is composed of 3
Thorax segments. It bears 3 pairs of legs(one on
each segment) and usually 2 pairs of wings.
Some insects have only 1 pair of wings,
others have none.
The abdomen is the posterior of the
Abdomen three body regions of an insect. It is
composed of 11 segments. The
abdomen bears the external genitalia
of the insect. In female insects these
consist of an ovipositor.
All living things are placed into groups depending on
common characteristics. The animal kingdom is informally
divided into two groups, the vertebrates and invertebrates.
Invertebrates are a group of animals that have no backbone,
unlike animals such as reptiles, amphibians, fish, birds and
mammals who all have a backbone
There are four stages all insect
goes through in their life
Larva: When an egg hatches, the larva emerges. Larvae are the feeding,
Egg: Insects non-feeding,stage of or in clusters. At this stage,may form a to
a lay fertilized transforming stage. This stage vulnerability
growing, nonreproductiveeggs singlydevelopment. During this stage, most
Pupa: isAdults are the reproductive stage of insects. They
Adult: control is minimal. The egg has a protective covering. These clusters of
chemical covering, such as the cocoon or Instead made by the
insects go through a process called molting.chrysalisof gradually growing
may or are enclosed in a protective live for a very brief period,
eggs often may not feed. Some material. However, egg clusters can be
butterfly. During this its skin cannot expand any into the adultold
insect transforms further. The stage,
larger, the larva eats until stage thelaid in protected, hidden locations to avoidskin
crushed. less. Control is possible during this stage
removed and day or Eggs may be
even one The stage between each molting is this stage, the only
splits andanto weather different form from the larva. At called an instar.
often is shed. and predators.
of development mechanical, such as crushing. It is critical to
possible control is but usually is more difficult.
control pests before they reproduce a new generation.
There is an important factor that govern the evolution of insects - their
molting, that lead to their capability of transformation of body, and adapt
to change. By molting, insects in different stage can have different shape
to make them suitable for their different living environment. Where there
is the new habitat, insects are usually the first group of animals to occupy
the habitat. Insects are the first animal to fly.
The Cambrian Period
543 to 490 Million Years Ago
The first known record of insects was found in the middle of the
cambrian period. The Cambrian Period marks an important point in the
history of life on earth, it is the time when most of the major groups of
animals first appear in the fossil record. This event is sometimes called
the "Cambrian Explosion", because of the relatively short time over
which this diversity of forms appears. It was once thought that the
Cambrian rocks contained the first and oldest fossil animals, but these
are now to be found in the earlier vendian strata
Many insects overwinter in a dormant state. They can be in any stage
of development — egg, larva, pupa, or adult. Insects spend the winter
in soil or dead plant material. Rough tilling of the soil can expose the
insect to fluctuating temperatures that may kill it. Removal and
disposal of plant debris also may eliminate overwintering insect
The deadliest creature on earth, the anopheles mosquito, is
responsible for more than 300 million cases of malaria each year, and
causes between one and three million deaths. Malaria affects 10% of
the world’s population, making it the leading mosquito-borne disease.
The 3,000 species of mosquito, including some 200 in North America,
do not all carry the same diseases. Mosquitoes can also carry dengue
and yellow fevers, encephalitis, elephantiasis, and canine heartworm.
There are 20,000 species of bee, including social, solitary, and parasitic. Bee
attacks generally occur when people stumble into a nest or otherwise
provoke bees. Africanized honeybees, also known as ‘killer bees,’ are an
exception. They were created when African bees were brought to Brazil in
1956 to breed a better honeybee. The effort failed and the bees escaped.
They have killed 1,000 people as they have moved north through Central
America to the southwestern U.S. The aggressive Africanized bees deliver a
nightmarish, agonizing death by swarming all over their victim. In the
Southwest, they have killed animals as large as horses.
Bedbugs, parasitic worms, and fleas are also leading
killers of humans. Fleas spread by rodents cause
plague. In the 14th century, plague killed three-
quarters of the population of Europe. Plague is rare
today and can usually be treated