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NCSO :: A Bug’s World 2012
Insect Worksheet
Insect: ___________________________________
Taxonomy (use common names, not scientific)
Class: __________________________
Order: _________________________
Family: ________________________
Habitat:
Diet:
Defenses:
Transportation:
Life Cycle:
Special Characteristics:
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NCSO :: A Bug’s World 2012
NCSO :: A Bug’s World 2012
A Little Bit About Bugs
Insects are a class (Class Insecta) within the arthropod phylum (Phylum Arthropoda). The word Arthropod
literally means jointed limbs. The arthropods are the first animal group to have jointed legs. ALL insects
have: Exoskeleton, 3 body segments, 6 legs that are jointed, 1 pair of antennae, wings, mouthparts, and
bilateral symmetry - a central line can divide the body into two identical halves, left and right.
**Vocabulary you should know is in BOLD**
Body Segments: Also called morphology. All insect bodies are divided into 3 major sections, the head,
thorax, and abdomen. Major body parts within each of these sections are also identified.
HEAD: The head of an insect is composed of mainly rigid segments called sclerites. The insect head is a
capsule that contains the compound eyes, mouthparts, and antennae.
Compound eyes: In most insects there is one pair of large, prominent compound eyes composed of
smaller units. There may be up to 30,000 smaller units in a compound eye.
Mouthparts:
Chewing Mouthparts are used for biting and grinding solid foods.
Sucking Mouthparts are primarily used for sucking liquids.
Antennae: Antennae function almost exclusively in sensory perception. Some of the information
that can be detected by insect antennae includes: motion and orientation, odor, sound, humidity,
and a variety of chemical cues.
THORAX: The insect thorax is divided into three parts: the prothorax (pro=first), mesothorax
(meso=middle), and metathorax (meta=last). Each segment consists of hardened plates, or sclerites. Each
of the three thoracic segments contains one pair of legs. Wings are found only on the meso- and
metathoracic segments.
Legs: The fore-legs are located on the prothorax, the mid-legs on the mesothorax, and the hind legs
on the metathorax. Like the mouthparts and antennae, insect legs are highly modified for different
functions, depending on the environment and lifestyle of an insect.
Walking legs (Ambulatory): are used for walking. The structure is similar to running legs.
Examples: Bugs (order Hemiptera), leaf beetles (order Coleoptera).
Running legs (Cursorial): are modified for running. Note the long, thin leg segments.
Examples: Cockroaches (order Blattaria), ground and tiger beetles (order Coleoptera).
Digging legs (Fossorial): fore legs are modified for digging. Examples: Ground dwelling
insects; mole crickets (order Orthoptera) and cicada nymphs (order Hemiptera).
Swimming legs (Natorial): are modified for swimming. These legs have long bristles on the
ankles. Examples: Aquatic beetes (order Coleoptera) and bugs (order Hemiptera).
Grasping legs (Raptorial): fore legs modified for grasping or catching prey. Examples:
Mantids (order Mantodea), giant water bugs and water scorpions (order Hemiptera).
NCSO :: A Bug’s World 2012
Wings: Insects have evolved many variations of the wings, and an individual insect may possess
more than one type of wing. In most living insects, the wings fold over the back of the insect. (In
some groups such as butterflies, the ability to fold the wings over the back has been lost.) Some
insect wings are covered with scales. The scales make the wings colorful. Examples: Butterflies,
moths and skippers (order Lepidoptera)
Membranous wings: are thin and more or less transparent, but
some are darkened. Examples: Dragonfiles and damselflies (order
Odonata), bees and wasps (order Hymenoptera)
Hardened wings (Elytra): are the hardened, heavily sclerotized
forewings of beetles and are modified to protect the hind wings
when at rest. Examples: All beetles (order Coleoptera).
Leathery wings (Tegmina): are the leathery forewings of insects
in the orders Grasshoppers, crickets and katydids, Cockroaches,
and Mantids. Like the hardened wings on beetles, the leathery wings help protect the
delicate hind wings. Examples: Grasshoppers, crickets and katydids (order Orthoptera),
Cockroaches (order Blattaria), Mantids (order Mantodea).
ABDOMEN: The abdomen contains a majority of the organ systems.
Ovipositor: The ovipositor is the egg-laying device found only in female insects. In some insects, the
ovipositor is highly modified and visible. In others, it may be needle or blade-like.
Metamorphosis: Insect Growth and Development
Insects go through several separate life stages: egg, larva or
nymph, pupa, and adult. Eggs are laid one at a time or in masses,
in or on plants, or even inside another insect! Eventually a larva or
nymph will emerge from the egg. There are usually several larval
or nymphal stages. During each stage the nymph grows larger and
molts, or sheds its outer skin before the next stage. They grow the
most during the last one or two stages. All the growing happens
during the larval or nymphal stages. The eggs, pupae, and adults
don't grow in size.
The two types of metamorphosis typical of insects are incomplete
metamorphosis (egg --> nymph --> adult) and complete
metamorphosis (egg --> larva --> pupa --> adult).