Metamorphosis
& Insect
Orders
Insects are the
most speciesrich group of
organisms on
earth as
indicated in this
species-scape.
The size of the
organism
reflects the
number of
described
species.
METAMORPHOSIS IN INSECTS
a rapid and complete transformation from an immature
larval life to a sexually adult form involving morphology,
function and habitat changes”.
It is when insects develop, grow and change form.
Metamorphosis infers "change." The term is of Latin and Greek
origins: meta means “change” and morphe means “form.”
Metamorphosis describes the series of changes through which an
insect passes in its growth from the egg stages, immature stages
to imago.
Ametabolous
(Direct
Development)
• The insects undergo
little or no metamorphosis
Paurometabolo
us (Gradual
Development)
• In the life cycle of these
insects there are three
stages, e.g., egg → nymph
→ adult. There is no pupal
stage
Hemimetabolo
us (Incomplete
Development)
• These insects also have
three stages in their life
namely, egg, young one and
adult. e.g., dragonflies,
mayflies and damselflies
Holometabolo
us (Complete
Development)
• Complete metamorphosis
or holometabolous
development is a kind of
rapid morphological change
during post embryonic
transformation in some
forms of insects where larva
has no similarity with the
adult and there is always a
pupal stage.
SUBPHYLUM HEXAPODA
Class Entognatha (3 order)
Class Insecta (29 order)
Characterized through the positioning of its mouthparts
Orthoptera (grasshoppers, crickets, katydids)
Greek "ortho" = straight, "ptera" = wing
Spot ID
• Jumping legs
• parallel-sided structure
of front wings
Orthoptera (grasshoppers, crickets, katydids)
Greek “orthos” = straight, “pteros” = wing
Orthoptera (grasshoppers, crickets, katydids)
Orthoptera (grasshoppers, crickets, katydids)
Spot ID
• Jumping hind legs
Orthoptera (grasshoppers, crickets, katydids)
Spot ID
• Jumping hind legs
• Some with ovipositor at hind
end
Coleoptera (beetles)
Greek “koleos”= sheath, “ptero”= wing
Coleoptera (beetles)
Coleoptera (beetles)
Spot ID
• Chewing mouthparts
Coleoptera (beetles)
Spot ID
• Chewing mouthparts
• Forewings (elytra)
form hard shell
covering hindwings
Lepidoptera (butterflies, moths)
Greek “lepido”= scale, “ptero”= wing
Lepidoptera (butterflies, moths)
Greek “lepido”= scale, “ptero”= wing
• Coiling-sucking mouthparts
Lepidoptera (butterflies, moths)
Greek “lepido”= scale, “ptero”= wing
• Coiling-sucking mouthparts
• Four wings covered with scales
Diptera (flies)
Latin “di”= two, “ptero”= wing
Diptera (flies)
Latin “di”= two, “ptero”= wing
Spot ID
• Two wings
Diptera (flies)
Latin “di”= two, “ptero”= wing
Spot ID
• Two wings
– Hind wings reduced
to halteres
Diptera (flies)
Latin “di”= two, “ptero”= wing
Spot ID
• Two wings
– Hind wings reduced
to halteres
• Sponging-sucking
mouthparts
– Except mosquitoes
and some others
that pierce skin
Diptera (flies)
Latin “di”= two, “ptero”= wing
Hymenoptera (bees, wasps, ants)
Greek “hymen”=membrane, “ptero”=wing
or
Hymen, the Greek god of marriage
because the forewing & hindwings are joined
together with small hooks
Hooks not shown
Hymenoptera (bees, wasps, ants)
Hymenoptera (bees, wasps, ants)
Spot ID
• Chewing mouthparts
Hymenoptera (bees, wasps, ants)
Spot ID
• Chewing mouthparts
• Four membranous wings
Hymenoptera (bees, wasps, ants)
Spot ID
• Chewing mouthparts
• Four membranous wings
• Waist often constricted
Hymenoptera (bees, wasps, ants)
Spot ID
• Chewing mouthparts
• Four membranous wings
• Waist often constricted
• Females with ovipositor or
stinger at end of abdomen
Hemiptera
(true bugs, also sometimes called Heteroptera)
Greek “hemisys” = half, “ptero” = wing
Hemiptera
(true bugs)
Greek “hemisys” = half, “ptero” = wing
Spot ID
• A beak: piercing-sucking mouthparts
Hemiptera
(true bugs)
Greek “hemisys” = half, “ptero” = wing
Spot ID
• A beak: piercing-sucking mouthparts
• Forewings covering hindwings
– Wing half membrane, half thickened
(hoppers, aphids, scales, cicadas)
Spot ID
• A beak: piercing-sucking mouthparts
• Forewings covering hindwings
– Wings all membranous
Dermaptera (earwigs)
Greek “derma” = skin, “ptero” = wing
Dermaptera (earwigs)
Greek “derma” = skin, “ptero” = wing
Spot ID
• Long skin-like hindwings folded
under very short forewings
Dermaptera (earwigs)
Greek “derma” = skin, “ptero” = wing
Spot ID
• Long skin-like hindwings folded
under very short forewings
• Pinchers off end of abdomen
Odonata (dragonflies, damselflies)
Greek “odon” = tooth
(referring to teeth on their mandibles)
Odonata (dragonflies, damselflies)
Odonata (dragonflies, damselflies)
Spot ID
• Long slender wings
Odonata (dragonflies, damselflies)
Spot ID
• Long slender wings
• Long thin body
BLATTODEA
(Termites)
Spot ID
• Pale, elongate body
• 2 pairs of membranous
wings of equal length only
present in reproductives
and shed after mating
• Mandibulate (chewing)
mouthparts
• Antennae about the same
length as the head
• Sometimes now classified
with Blattodea because
their DNA suggests that
they are specialized
roaches
Blattodea (roaches)
Latin “blatta” = cockroach
Blattodea (roaches)
Blattodea (roaches)
Spot ID
• Flat
Blattodea (roaches)
Spot ID
• Flat
• Spiny legs
Blattodea (roaches)
Also called Blattaria, Greek “Blatta” = cockroach
Spot ID
• Flat
• Spiny legs
• Long antennae
Neuroptera (ant lions, lacewings,
mantidflies)
Greek "neuron" = nerve and "ptera" = wings
Spot ID
• four membranous netveined wings
• forewings and
hindwings about the
same size
Neuroptera (ant lions, lacewings,
mantidflies)
Greek "neuron" = nerve and "ptera" = wings
Spot ID
• Larvae have elongated
mandibles adapted for
piercing and sucking
• Oliver the Owlfly
larva is an example
• Antlion larvae
(doodlebugs)
Mantodea (praying mantises)
Greek “mantis” = prophet
Spot ID
• two grasping, spiked
forelegs often held in
“praying” position
• Triangular, swiveling
head with large
compound eyes
Phasmatodea (walking stick insects)
Also Phasmida, Greek “phasm” = phantom
Spot ID
• cylindrical stick-like
body or flattened,
leaflike shape
• long, slender antennae
• sometimes have wings
Thysanura (silverfish, bristletails)
Greek "thysano-" = fringed, "ura" = tail
Spot ID
• three long caudal (tail)
filaments
• Silverfish are so called
due to the silvery
glitter of the scales
covering their bodies
• flattened bodies, may
be elongated or oval in
shape
Ephemeroptera (mayflies)
Also Ephemeroptera, Greek "ephemera"
=short-lived
Spot ID
• delicate bodies and
gauzy, fragile wings
• two or three long
threads (caudal
filaments) at end of
abdomen
• Adults have no
functional mouthparts
Plecoptera (stoneflies)
Greek "pleco" = braided, "ptera" = wing
Spot ID
• complex venation of two
pairs of wings, which are
membranous and fold
flat over the back
• legs each end in two
claws
• long, multi-segmented
antennae
Mecoptera (scorpionflies)
Greek “meco-” = long, “ptera” = wings
Spot ID
• abdomen is cylindrical,
and typically curves
upwards in the male,
superficially resembling
the tail of a scorpion
• wings are narrow in
shape, with numerous
cross-veins
Trichoptera (caddisflies)
Greek “trich” = hair, ptera = wing
Spot ID
• small moth-like with
two pairs of hairy
membranous wings
• Aquatic larvae, adults
usually found near
aquatic habitats
Siphonaptera (fleas)
Greek "siphon“ = tube or pipe, "aptera" =
wingless
Spot ID
• Wingless (adaptation to
ectoparasitism)
• 1-10mm long
• Mouthparts are sucking and
piercing
• Hind legs are enlarged for
jumping
• Laterally flattened
Thysanoptera (thrips)
Greek "thysano-" = fringed, “ptera" = wing
• Very small insects
with a range of 1/32
to 1/8 inch in length
• Feed on plants,
considered crop
pest
Some Common Insects