Subphylum Uniramia
centipedes, millipedes, insects
Arthropoda Classification
Phylum Arthropoda
Subphylum Uniramia- (terrrestrial mandibulates)
Class Chilopoda- centipedes
Class Diplopoda- millipedes
Class Insecta- insects
Subphylum Crustacea- (aquatic mandibulates) lobsters,
crabs, crayfish, shrimp, sow bugs (pill bugs), krill and
barnacles
Subphylum Chelicerata
Class Arachnida- spiders, scorpions, ticks, and mites
Class Merostomata- horshoe crab
Class Pycnogonida- sea spiders
Subphylum Trilobita- trilobites (extinct)
Class Chilopoda
• Includes the centipede
• 1 pair of legs per body segment
• Flat body
• Fast
• Mainly carnivores (limbs on first
appendage are poisonous claws)
Class Diplopoda
• Includes the millipede
• 2 pairs of legs per body
segment
• Cylindrical Body
• Slow
• Mainly herbivorous
Arthropoda Classification
Phylum Arthropoda
Subphylum Uniramia- (terrrestrial mandibulates)
Class Chilopoda- centipedes
Class Diplopoda- millipedes
Class Insecta- insects
Subphylum Crustacea- (aquatic mandibulates) lobsters,
crabs, crayfish, shrimp, sow bugs (pill bugs), krill and
barnacles
Subphylum Chelicerata
Class Arachnida- spiders, scorpions, ticks, and mites
Class Merostomata- horshoe crab
Class Pycnogonida- sea spiders
Subphylum Trilobita- trilobites (extinct)
Common Insect Orders
• Orthoptera- (“straight wing”) grasshoppers,
crickets, cockroaches, locusts, katydids
• Hemiptera- (“half wing”) true-bugs, stinkbugs,
bed bugs, water striders
• Coleoptera- (“sheath wing”) beetles, weevils
• Lepidoptera- (“scale wing”) butterflies, moths
• Hymenoptera- (“membranous wing”) bees, ants,
wasps, sawflies
• Diptera- (“two wings”) flies, mosquitoes, gnats
Order Orthoptera
Order Coleoptera
Order Odonata
Order Lepidoptera
Order Diptera
Order Hymenoptera
Class Insecta
Important characteristics
for survival:
1. They can fly
A. Escape danger
B. Find a mate
C. Look for food
D. Search for suitable
environment
2. They have tremendous reproductive capabilities
• Can produce thousands of eggs in a single day
3. They have great variety within the class. They are
specialized to occupy different niches.
Niche
(1) The specific area where an organism inhabits.
(2) The role or function of an organism or species in an ecosystem.
(3) The interrelationship of a species with all the biotic and abiotic factors
affecting it.
•Little competition for food
•Little competition for living space
Basic Insect Structure
The following characteristics distinguish insects from other
arthropods
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Three pairs of walking legs
Wings usually present
Body divided into 3 segments (head, thorax, abdomen)
One pair of sensory antennae
Legs
• Fly (Order Diptera) legs have tiny claws and
sticky pads for climbing smooth surfaces
• Grasshopper (Order Orthoptera) heavily
muscled hind legs for jumping
• Bees (Order Hymenoptera) have combs and
hairs on their legs- important for carrying
pollen
Wings
• Membranous wings- thin, transparent, contain
supporting veins, flying wings of most insects, both
pairs of wings in Order Hymenoptera are membranous
• Scale covered wings- both pairs in butterflies and
moths (Order Lepidoptera)
• Leatherlike wings- grasshopper (Order Orthoptera) has
flying wings covered by leatherlike wings that protect
the flying wings
• Horny wings (elytra)- thick hard shields that protect the
flying wings of beetles (Order Coleoptera)
• Order Hemiptera only have 1 pair of wings and half the
wing is leatherlike and the other half is membranous
Mouthparts
•Labrum- upper lip
•Labium- lower lip
•Mandibles- chewing
appendages
•Maxillae- manipulate
food when eating
•Palps- sensory
appendages
•Proboscis- coiled tube, in
Order Lepidoptera used to
siphon nectar from
flowers
•Rostrum- long beak that
folds under the insects
body in Order Hemiptera
used to pierce food
Legend:
a, antennae
c, compound
eye
lb, labium
lr, labrum
md, mandibles
mx, maxillae
hp, hypopharynx
The development of insect mouthparts
from the primitive chewing mouthparts
of a grasshopper in the centre (A), to the
lapping type (B) of a bee, the siphoning
type (C) of a butterfly and the sucking
type (D) of a female mosquito.
Digestion
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Mouth
Esophagus
Crop
Gizzard
Stomach
Intestines
Anus
Foregut
Salivary glands- secretions from these moisten food
in the mouth
Midgut
Gastric ceca- pouchlike organs that surround the
stomach and supply it with digestive juices
Hindgut
Respiration
• Tracheal systemseries of tubules
that run
throughout the
insects body and
open to the
outside through
pores called
spiracles, this
system is sufficient
itself for
respiration
Circulation and Excretion
• Tubular heart
• Hemolymph- clear or yellowish fluid in insects,
carries nutrients and waste
• Open circulatory system
• Malpighian tubules- ring of thin tubules
encircling the juncture of the stomach and
intestine, extract nitrogenous wastes from
hemolymph and pass them into the intestine
so they can be excreted
Response
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Antennae- smell
Mouthparts have taste receptors
Hairs all over the body sense touch
Compound eyes- usually large relative to the head,
large field of view
• Grasshoppers (Order Orthoptera) have a tympanum
which is a membrane covered chamber in the first
abdominal segment that allows them to hear.
• Stridulation- producing sound by rubbing body parts
together
Reproduction
• Sexual reproduction
• Not hermaphroditic
• Females have an ovipositor which is a pointed
extension at the end of the abdomen, deposits
fertilized eggs
Metamorphosis-series of developmental changes.
1. Incomplete metamorphosis-involves 3 basic stages
1. Egg
2. Nymph (naiad if in water)
3. Adult
Orthoptera, Hemiptera
2. Complete metamorphosis- involves 4 stages
1. Egg
2. Larva
3. Pupa
4. Adult
Process followed by 90% of all insects
Coleoptera, Lepidoptera, Hymenoptera, Diptera
Larva (common names)
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Maggots- flies
Grubs- beetles
Wigglers- mosquitoes
Caterpillars- moths and butterflies
Incomplete Metamorphosis