METAMERIC, EUCOELOMATE ECDYSOZOANS: NON

METAMERIC, EUCOELOMATE
ECDYSOZOANS: NON-ARTHROPODS
“ARTHROPOD COUSINS”
AS ALWAYS, PHYLOGENY FIRST!
Kingdom: Animalia
Subkingdom:
Eumetazoa
Subkingdom:
Parazoa
Phylum:
Porifera
Phylum:
Placozoa
Clade:
Bilateria
Clade:
Radiata
Phylum:
Cnidaria
Phylum:
Ctenophora
Division:
Protostomia
Superphylum:
Lophotrochozoa
Division:
Deuterostomia
Superphylum:
Ecdysozoa
PHYLUM: ONYCHOPHORA

Distinguishing
characteristics of
Phylum Onychophora:
 These are the “velvet
worms”
 Body centipede-like, but
without jointed legs
(“lobopods”)
 Organisms equipped with
two oral “slime glands”
that shoot strands of
mucus (over 1 ft!) in
order to entangle prey
PHYLUM: TARDIGRADA

Distinguishing
characteristics of
Phylum Tardigrada:
 These are the “water
bears”
 Minute animals found on
aquatic an marine
vegetation
 Excretory system similar
to Malpighian tubules of
insects
 Can contract into a state
of suspended animation
called cryptobiosis
ONYCHOPHORA & TARDIGRADA:
TRAITS SHARED WITH ARTHROPODS

Onychophora and Tardigrada share with Arthropods:
 metameric body plan
 outer cuticle shed by ecdysis (Ecdysozoa)
 body cavity & fluid called hemocoel & hemolymph

Historically, it was thought that “myriapods” (e.g.
centipedes) evolved directly from velvet worms, and
that insects evolved directly from myriapods

Evidence shows all arthropods are more closely
related to each other than they are to either
Onychophora or Tardigrada, although they all may
form a monophyletic group called Panarthropoda
PHYLUM ARTHROPODA:
BEGINNINGS?
Tullymonstrum,
a “Tully monster”
PHYLUM ARTHROPODA:
BEGINNINGS?
Opabinia,
an Opabiniid
PHYLUM ARTHROPODA:
BEGINNINGS?
Anomalocaris,
a proto-arthropod
Zebra Swallowtail
Marbled Orb
Weaver
Presented by
Praying Mantis
ROB
Brownish-Gray
Fishing Spider
PHYLUM: ARTHROPODA

Distinguishing
characteristics of
Phylum Arthropoda:
 These are the
arthopods!
 Inverterbrates with
jointed legs
 All have chitinous
exoskeleton
 All have a hemocoel
and blood fluid called
hemolymph
PHYLUM ARTHROPODA:
FUN FACTS

Arthropoda is the
largest phylum in the
animal kingdom

Over 900,000 described
species

Could be as many as
5,000,000 more

Artrhopods outnumber
200,000,000 to 1!
PHYLUM ARTHROPODA:
WHY SO MANY ARTHROPODS?

Chitinous exoskeleton
gives arthropods selective
advantage in harsh
environments

Evolved a variety of
defenses to avoid predation

LOTS of offspring—
r-selected

Effectively infinite number of
niches allows small animals
to adapt & radiate
Monarch Butterfly
(toxic)
Viceroy Butterfly
(not toxic)
Dogbane Leaf Beetle
PHYLUM ARTHROPODA:
CLASSIFICATION & TAXONOMY

There are “currently”
5 subphyla of arthropods:
 Subphylum:
Trilobitomorpha*
 Subphylum: Chelicerata
 Subphylum: Crustacea**
 Subphylum: Hexapoda
 Subphylum: Myriapoda
* = extinct
** = paraphyletic
NOT TRILOBITES, BUT…?????
(e.g. Dickinsonia & Sprigginia
SUBPHYLUM: TRILOBITOMORPHA

Fossil forms only

Body divided into three
regions:
 cephalon
 thorax
 pygidium

Thorax & pygidium
further divided into
3 longitudinal lobes:
 median or central lobe
 2 pleural lobes
SUBPHYLUM: TRILOBITOMORPHA
SUBPHYLUM: CHELICERATA
Distinguishing characters:
All chelicerates possess a
medial pair of feeding
appendages called chelicerae
 Chelicerae may be modified
into either jaws, fangs, or as
part of a capitulum
Chelicerae are usually flanked
laterally by a second pair of
appendages called pedipalps
SUBPHYLUM CHELICERATA:
GENERAL FORM & FUNCTION

The body of chelicerates is divided into 2 regions:
 Prosoma (cephalothorax)
–
Contains head, feeding, & sensory structures
 Opisthosoma (abdomen)
–

Contains all other major organs & structures
Breathing is often accomplished by either book gills
or book lungs
 A few arachnids have spiracles that open into tracheae

Excretory function is accomplished by means of
Malpighian tubules
Book lungs of scorpion
SUBPHYLUM CHELICERATA:
CLASSIFICATION & TAXONOMY

There are 3 classes in
Subphylum Chelicerata:
 Class: Merostomata
 Class: Pycnogonida
 Class: Arachnida
CLASS: MEROSTOMATA

Distinguishing
characteristics of
Class Merostomata:
 These are the
horsheshoe crabs
(extant) and the
sea scorpions (extinct)
 Opisthosoma
terminates in a
spike-like telson
CLASS MEROSTOMATA:
HORSESHOE CRAB BLOOD

The hemolymph of
horseshoe crabs uses
copper as an oxygen
carrier instead of iron
(hemocyanin), so
“blood” is blue

Horseshoe crab “blood” is
harvested because it
contains amoebocytes
that react with certain
bacterial toxins
 LAL - test
CLASS MEROSTOMATA:
MATING ORGY
CLASS: PYCNOGONIDA

Distinguishing
characteristics of
Class Pygnogonida:
 These are the sea
spiders
 Opisthosoma is highly
reduced
 No special respiratory
or excretory structures
 4 to 6 pairs of walking
legs
CLASS: ARACHNIDA

Distinguishing
characteristics of
Class Arachnida:
 These are the spiders,
scorpions, ticks &
chiggers, daddy-longlegs, and others
 Adults almost always
have 4 pairs of walking
legs
CLASS ARACHNIDA:
CLASSIFICATION & TAXONOMY

There are 12 orders of
Class Arachnida—here
are 6 common ones:
 Order: Araneae
 Order: Scorpiones
 Order: Opiliones
 Order: Acari
 Order: Solifugae
 Order: Thelyphonida
ORDER: ARANEAE

Characteristics of
Order Araneae:
 These are the spiders
 Chelicerae bear hollow
fangs attached to
venom glands
 Usually web-spinning
organs called
spinnerets at posterior
of abdomen
 All are carnivorous, but
habits highly variable
Black-and-yellow argiope
ORDER: ARANEAE
Grass Spider
ORDER: ARANEAE
Rabid Wolf Spider
ORDER: ARANEAE
Goldenrod Crab Spider
ORDER: ARANEAE
Ozark (or “Missouri”) Tarantula
ORDER: ARANEAE
Latrodectus mactans
Loxoceles reclusa
ORDER: SCORPIONES

Characteristics of
Order Scorpiones:
 These are the scorpions
 Pedipalps modified into
pincers
 Opisthoma divided into
preabdomen &
postabdomen
 Postabdomen
terminates in a sting
 Book lungs only
ORDER: OPILIONES

Characteristics of
Order Opiliones:
 These are the daddy-
long-legs (or harvestmen
if you’re a weirdo yank)
 No constriction between
prosoma and
opisthosoma
 Legs long and slender
 THESE ARE NOT
SPIDERS !!!
 Closest relatives are mites
ORDER: ACARI

Characteristics of
Order Acari:
 These are the mites,
ticks, and “chiggers”
 Prosoma and
opisthosoma fused
 Parasitic forms have
modified chelicerae and
pedipalps forming a
capitulum that
terminates in a barbed
rostrum
ORDER: SOLIFUGAE

Characteristics of
Order Solifugae:
 These are the camel
spiders, sun spiders, or
wind scopions
 Body spider-like, but
chelicerae enlarged and
lacking hollow fangs;
pedipalps absent
 Spinnerets absent
ORDER: THELYPHONIDA

Characteristics of
Order Thelyphonida:
 These are the whip-
scorpions or
“vinegaroons”
 Pedipalps large, curved,
& pincer-like
 Opisthosoma
terminates in flagellalike “tail” capable of
firing acetic acid
SUBPHYLUM: CRUSTACEA
Characteristics:

Only arthropod group
with two pairs of
antennae

1 pair of mandibles, and
2 pairs of maxillae
(usually)

Appendages are
biramous (= two
branches)
Diversity of Crustacea
SUBPHYLUM CRUSTACEA:
PHYLOGENETIC ISSUES

“Crustacea” is paraphyletic with Hexapoda

Together, crustaceans and hexapods form a
monophyletic clade called Pancrustacea

Current thought is that hexapods (e.g. insects) evolved
directly from a malacostracan crustacean ancestor

Beyond this, primary hypothesis is that Pancrustacea,
Myriapoda, and Chelicerata are indeed distinct groups;
and that they diverged from 1 or 2 ancestral “protoarthropod” groups at roughly the same time…
SUBPHYLUM “CRUSTACEA”
CLASSIFICATION & TAXONOMY

There are 5 classes in
Subphylum Crustacea—
the 3 most common are:
 Class: Branchiopoda
 Class: Maxillopoda
 Class: Malacostraca
CLASS: BRANCHIOPODA

Distinguishing
characteristics of
Class Branchiopoda:
 These are the water
fleas, tadpole shrimp,
and fairy shrimp
 Legs flattened and
leaflike; serve as
primary respiratory
strucure
 Beyond this, body forms
variable
CLASS BRANCHIOPODA:
CLASSIFICATION & TAXONOMY

There are 4 orders of
Class Branchiopoda

The most common one
is Order: Cladocera
 These are the water
fleas
 Minute crustaceans,
resemble fleas
CLASS BRANCHIOPODA:
ONE OF MY FAVS
Tadpole shrimp are pretty rad.
CLASS: MAXILLOPODA

Distinguishing
characteristics of
Class Maxillopoda:
 Ostracods, copepods
(cyclops), & others
 No typical abdominal
appendages
 Adults may retain a
unique, nauplius eye
between or posterior to
compound eyes
CLASS MAXILLOPODA:
CLASSIFICATION & TAXONOMY

There are 6 subclasses
of Class Maxillopoda.

The two most common
are:
 Subclass: Ostracoda
 Subclass: Copepoda
SUBCLASS: OSTRACODA

Characteristics of
Subclass Ostracoda:
 Ostracods
 Superficially resemble
minute clams
 Body enclosed in a
bivalve carapace
SUBCLASS: COPEPODA

Characteristics of
Subclass Copepoda:
 Copepods or “cyclops”
 Body paddle-shaped
 Antennules often longer
than other appendages
 Medial eye cluster gives
appearance of a cyclops
 Free-living forms have
extreme ecological
importance in both marine
and freshwater habitats
CLASS: MALACOSTRACA

Distinguishing
characteristics of
Class Malacostraca:
 These are the “major
crustaceans”—
crawdads, lobsters,
crabs, shrimp, pill bugs
 Most biodiverse class of
crustaceans
 19-20 body segments: 5
head, 8 thorax, 6-7
abdominal
CLASS MALACOSTRACA:
CLASSIFICATION & TAXONOMY

There are 4 orders in
Class Malacostraca.

Three of the most
common are:
 Order: Amphipoda
 Order: Isopoda
 Order: Decapoda
ORDER: AMPHIPODA

Characteristics of
Order Amphipoda:
 These are the beach
fleas & scuds
 Body laterally
compressed
 Carapace absent
 Uniramous appendages
 Uropods do not form
tail fan as in true shrimp
ORDER: AMPHIPODA
Giant amphipods measuring over 1 foot (!)
have recently been discovered in deep
ocean environments.
ORDER: ISOPODA

Characteristics of
Order Isopoda:
 These are sowbugs, pill
bugs, wood lice, or
roly-polies
 7 pairs of legs
 Only group of
crustaceans that can be
truly terrestrial
ORDER: DECAPODA

Characteristics of
Order Decapoda:
 These are the most
familiar crustaceans—
crabs, lobsters,
crayfish, & shrimp
 All have 5 pairs of
walking legs
If you can boil it and eat it,
it’s probably a decapod!
DECAPOD DIVERSITY
DECAPOD DIVERSITY
Ozark blind crayfish, Orconectes australis
CRAYFISH—A TYPICAL CRUSTACEAN:
GENERAL FORM & FUNCTION

Body: the body is divided into two major
regions—cephalothorax and abdomen
 Cuticle of head extends posteriorly to form
dorsolateral covering called a carapace
 Carapace may project forward to form nose-like
rostrum
 Abdomen terminates in a telson, flanked by two
pairs of uropods (telson + uropods = tail fan)
CRAYFISH—A TYPICAL CRUSTACEAN:
GENERAL FORM & FUNCTION

Appendages: may be either biramous (twoarmed) or uniramous
 Biramous appendages have a medio-proximal
endopod, and a latero-distal exopod that join at a
common epipod
 There are 4 groups of appendages:
–
–
–
–
sensory appendages
mouthparts
walking legs
swimmerets
CRAYFISH—A TYPICAL CRUSTACEAN:
GENERAL FORM & FUNCTION

Sensory appendages are biramous and
include long, lateral anntennae and shorter,
medial antennules

Mouthparts are biramous and include the
innermost, jaw-like mandibles; 2 pairs of
maxillae, and 3 pairs of maxillipeds
 2nd maxilla bears a flat scaphognathite (gill bailer)
to keep water moving over the gills
 Endopods and exopods are more pronounced in
maxillipeds
CRAYFISH—A TYPICAL CRUSTACEAN:
GENERAL FORM & FUNCTION

Walking legs (5 pairs) are uniramous
 1st pair of walking legs bear pincers, or chelae
 Epipods of all walking legs (and 2nd & 3rd
maxillipeds) form gills

Swimmerets are biramous and found on the
abdomen only
 In males, the first pair of swimmerets are modified
into club-like copulatory structures
Figure 14.21
CRAYFISH—A TYPICAL CRUSTACEAN:
GENERAL FORM & FUNCTION
CRAYFISH—A TYPICAL CRUSTACEAN:
FEEDING & DIGESTION

Mouthparts guide food
to mandibles, and then
into the mouth

Digestive system:
1)
2)
3)
4)
5)
6)
mouth
esophagus
cardiac stomach
(w/ gastric mill)
pyloric stomach
intestine
anus
Gastric mill in cardiac stomach of
a crayfish
Digestive gland
secretes digestive
enzymes into the
pyloric stomach
CRAYFISH—A TYPICAL CRUSTACEAN:
EXCRETORY SYSTEM

Excretion is
accomplished by means
of two labyrinth-like
green glands, internal
to and just below the
bases of the antennae

Nitrogenous waste is
expelled from the green
glands through an
excretory pore
Interior of green glands
CRAYFISH—A TYPICAL CRUSTACEAN:
RESPIRATION & CIRCULATION

Arthropods have an
open circulatory
system:
 Water enters branchial
chamber and brings
oxygen over gills
 Oxygen-rich hemolymph
leaves gills and enters
pericardial sinus
 Hemolymph enter heart
through heart ostia,
which pumps hemolymph
out through arteries
CRAYFISH—A TYPICAL CRUSTACEAN:
NERVOUS SYSTEM

Nervous system
consists of:
 suprapharyngeal
ganglion
 subpharyngeal
ganglion
 circumpharyngeal
connectives
 ventral nerve cord
CRAYFISH—A TYPICAL CRUSTACEAN:
REPRODUCTION

Most crustaceans are
dioecious

Gametes are produced in
a gonad— testis or ovary

Gametes travel through a
gonoduct—sperm duct
or oviduct

Gametes exit through a
gonopore

Fertilization is external
Female with brood
?????
SUBPHYLUM: HEXAPODA

Distinguishing
characteristics of
Subphylum Hexapoda:
 These are the insects
and their relatives
 All have 3 pairs of
uniramous, thoracic
walking legs
 Body segments
(somites) grouped into
three tagmata—head,
thorax, & abdomen
SUBPHYLUM HEXAPODA:
SEGMENTATION VS. TAGMATIZATION


A body segment
(metamere or somite) is
simply one out of a
number of repeated body
units.
Head
Thorax
A tagma is a group of
somites that performs a
distinct set of functions:
 Head = sensory
 Thorax = flight &
Abdomen
locomotion
 Abdomen = all other major
body functions
The plural of tagma is tagmata
SUBPHYLUM HEXAPODA:
CLASSIFICATION & TAXONOMY

There are 2 (or 3) classes
in Subphylum Hexapoda:
 Class: Entognatha
 Class: Insecta
NON-INSECT HEXAPODS:
CLASS ENTOGNATHA

Characteristics of
Class Entognatha:
 These are the non-
insect hexapods—e.g.
springtails, etc.
 All have internalized,
stylet-like mouthparts
 Mandibles are
monocondylic (1 point
of articulation)
CLASS ENTOGNATHA:
ORDER COLLEMBOLA

Distinguishing
characteristics of
Order Collembola:
 These are the
“springtails”
 Posterior abdomen
bears a forked furcula
for jumping
 Ventral structure called
a collophore aids in
water intake & excretion
CLASS: INSECTA

Characteristics of
Class Insecta:
 These are the insects!
 Hexapods with external
mouthparts (usually)
 Mandibles are
dicondylic—2 points of
muscle attachment
CLASS INSECTA:
GENERAL STRUCTURE & FUNCTION

Head bears:
 1 pair of antennae
 2 compound eyes
 3 simple eyes (ocelli)
 3 pairs of mouthparts
–
mandibles
–
maxillae
–
labia
CLASS INSECTA:
GENERAL STRUCTURE & FUNCTION
CLASS INSECTA:
GENERAL STRUCTURE & FUNCTION

Thorax bears:

legs

wings (usually 2 pair)
–
Rapid wingbeats
possible due to:
1)
asynchronous
nerve impulses
2)
fibrillar flight
muscles
CLASS INSECTA:
GENERAL STRUCTURE & FUNCTION
INSECT LEGS
Cursorial = running
Saltatorial = jumping
Fossorial = digging
Raptorial = predatory
CLASS INSECTA:
GENERAL STRUCTURE & FUNCTION

Abdomen bears:
 Respiratory structures
(spiracles)
 Copulatory / genital
structures
 Anus
Female ichneumon wasp ovipositing
CLASS INSECTA:
SENSORY & NERVOUS SYSTEM

Nervous system
resembles that of other
arthropods:
 In insects, ganglia & other
cephalic nerve masses
usually referred to as a
brain
 Brain connects to
ventral nerve cord
An insect brain
CLASS INSECTA:
SENSORY & NERVOUS SYSTEM

Mechanoreception is
accomplished by means
of sensilla
 A sensillum is either a
hairlike projection or
individual body cells
attached to a nerve
ending
 Although a large number
of sensilla may be found
on the antennae, sensilla
are generally found
all over the body
Diagram showing antenna
with sensilla
CLASS INSECTA:
SENSORY & NERVOUS SYSTEM

Chemoreception is
accomplished by
bundles of sensory cells
located in sensory pits
 Olfactory (smelling)
sensory pits are generally
concentrated on the
antennae
 Gustatory (tasting)
sensory pits are generally
located on feeding palps,
but may also be located
on feet (tarsi)
Some insects, like butterflies, can
“taste” with their feet.
CLASS INSECTA:
SENSORY & NERVOUS SYSTEM

Visual reception is
accomplished by both
compound eyes and
ocelli
 Compound eyes are
comprised of hundreds or
thousands of individual
facets called ommatidia
–
Ommatidia act together
to sense shape & color
 Ocelli sense light changes
CLASS INSECTA:
SENSORY & NERVOUS SYSTEM

Auditory reception is
accomplished using
either hair sensilla or
tympanal organs
 Tympani may be located
on the thorax, abdomen,
or legs
 Tympani present in
grasshoppers, crickets,
katydids, cicadas, and
butterflies & moths
CLASS INSECTA:
FEEDING & DIGESTION

Insects may be either
herbivorous or
carnivorous

Digestive system:
 Mouth
 Pharynx
 Esophagus
 Crop
 Gizzard
 Gastric caeca & stomach
 Intestine
 Rectum
 Anus
Some carnivorous insects are
parasitoids
CLASS INSECTA:
FEEDING & DIGESTION
CLASS INSECTA:
EXCRETION

Excretion is
accomplished by means
of special structures called
Malpighian tubules
 Tubules at the end of midgut
absorb posassium acid urate
from hemocoel, and then
pass urate down to rectum
 Water & potassium are
reabsorbed by the rectum
 Uric acid is expelled out the
anus with solid waste
CLASS INSECTA:
EXCRETION
CLASS INSECTA:
CIRCULATION

Insects have an open
circulatory system
consisting of a
single blood vessel:
 Dorsal aorta pumps
hemolymph into hemocoel
via peristaltic waves
 Beyond this, hemolymph
circulates freely in the
hemocoel
 Hemolymph enters heart
again through ostia
CLASS INSECTA:
CIRCULATION
CLASS INSECTA:
RESPIRATION

Most insects breathe
using a tracheal system
 Air enters tracheae
through abdominal
spiracles
 Tracheae branch to
become tracheoles
 Tracheoles deliver oxygen
to individual cells
throughout the body
Abdominal spiracles in a caterpillar
CLASS INSECTA:
REPRODUCTION

Insects are dioecious, and fertilization is almost
always internal
 Exception: some primitive forms deposit sperm encased in a
spermatophore, and leave it to be “found” by a female

Male system: testes  vas deferens  seminal
vesicle (w/ accessory glands)  ejaculatory duct 
aedeagus  genital opening

Female system: ovaries  lateral oviduct 
common oviduct (w/ accessory glands)  vagina 
vulva; separate spermatheca for sperm storage
CLASS INSECTA:
REPRODUCTION
Male
Female
CLASS INSECTA:
REPRODUCTION
Spermatophore
Beetles in copula, aedeagus extended
CLASS INSECTA:
GROWTH & DEVELOPMENT

Insects have evolved
3 different growth &
development strategies:
 Ametabolous
develoment
–
juveniles are minature
adults
 Hemimetabolous
development
–
juveniles are called
nymphs; no pupal stage
 Holometabolous
development
–
Juveniles are called larvae;
pupal development
HEMIMETABOLOUS DEVELOPMENT
Dog-day
Cicada
HOLOMETABOLOUS DEVELOPMENT
CLASS INSECTA:
CLASSIFICATION & TAXONOMY

There are 29 orders in
Class Insecta.
Know these 12:
 Ametabolous orders:
– Order: Thysanura
 Hemimetabolous orders:
–
–
–
–
–
–
–
Order: Ephemeroptera
Order: Odonata
Order: Mantodea
Order: Blattodea
Order: Orthoptera
Order: Phasmatodea
Order: Hemiptera
 Holometabolous orders:
–
–
–
–
Order: Coleoptera
Order: Lepidoptera
Order: Diptera
Order: Hymenoptera
AMETABOLOUS INSECTS
ORDER: THYSANURA

Characteristics of
Order Thysanura:
 These are the silverfish
& firebrats
 Body brown or shiny
silver with three long
caudal filaments
 Only dicondylic,
ametabolous group of
insects
A silverfish
HEMIMETABOLOUS INSECTS
ORDER: EPHEMEROPTERA

Characteristics of
Order Ephemeroptera:
 These are the mayflies
 Nymphs aquatic with 3
caudal filaments
 Adults have highly
veined membranous
wings; abdomen with 2
or 3 caudal filaments
ORDER: ODONATA

Characteristics of
Order Odonata:
 These are the
dragonflies &
damselflies
 compound eyes
occupying most of head
 Long, slender abdomen
 Nymphs are aquatic
predators
ODONATA DIVERSITY
ORDER: MANTODEA

Characteristics of
Order Mantodea:
 These are the praying
mantids (mantises)
 Front legs raptorial and
armed with spines
 Thorax elongate
 Hindwings broad and
fan-like
MANTODEA DIVERSITY
ORDER: BLATTODEA

Characteristics of
Order Blatodea:
 These are the
cockroaches
 Body oval and flattened
 Head concealed by
shieldlike prothorax
 Abdomen bearing 2
posterior cerci
Roaches can vector diseases like
salmonella and hepatitis.
ORDER: ORTHOPTERA

Characteristics of
Order Orthoptera:
 These are the
grasshoppers, katydids,
& crickets
 Hindlegs modified for
Eastern lubber grasshopper
jumping
 Forewings narrow &
leathery; hindwings
broad & membranous
True katydid
ORDER: PHASMATODEA

Characteristics of
Order Phasmatodea:
 These are the stick
insects
 Body long and stick-
like
 Wings absent
 Cerci present
ORDER: HEMIPTERA

Characteristics of
Order Hemiptera:
 These are the “true
bugs” plus cicadas,
aphids, & hopping bugs
 Piercing-sucking
mouthparts
 Only half of forewing
membranous in some
groups (“true bugs”)
HEMIPTERA DIVERSITY
HOLOMETABOLOUS INSECTS:
ORDER COLEOPTERA

Characteristics of
Order Coleoptera:
 These are the beetles
 Forewings hardened
and covering abdomen;
(wing covers = elytra)
 Most diverse order of
animals on the planet
Different species of lightning
beetles (Lampyridae) have
different flash patterns.
COLEOPTERA DIVERSITY
COLEOPTERA DIVERSITY:
LOCAL STUFF
Tiger beetle
June beetle
Longhorn beetle
American burying beetle
THE BEATLES
ORDER: LEPIDOPTERA

Characteristics of
Order Lepidoptera:
 These are the moths &
butterflies
 Both pairs of wings
covered with
microscopic scales
 Mouthparts, when
present, modified into a
coiled sucking tube
(maxillae)
Eastern tiger swallowtail
LEPIDOPTERA DIVERSITY
ORDER: DIPTERA

Characteristics of
Order Diptera:
 These are the
mosquitoes, gnats,
crane flies, & true flies
 All have a single pair of
wings (if present)
Common house fly
ORDER: DIPTERA
Striped horse fly
ORDER: DIPTERA
Hover fly
ORDER: HYMENOPTERA

Characteristics of
Order Hymenoptera:
 These are the wasps,
bees, & ants
 Two pairs of
membranous wings
with veins reduced
 Female ovipositor may
be modified into stinger
 Invertebrate group with
the highest number of
eusocial taxa
Leaf-cutter ants use leaves to farm
a fungus as their food source.
ORDER: HYMENOPTERA
A cicada killer wasp
ORDER: HYMENOPTERA
A “cow killer” velvet ant
SUBPHYLUM: MYRIAPODA

Distinguishing
characteristics of
Subphylum Myriapoda:
 These are the centipedes
and millipedes
 Body divided into two
regions—head & trunk
 4 pairs of uniramous
mouthparts
 4 classes—2 primary:
–
–
Class: Diplopoda
Class: Chilopoda
CLASS: DIPLOPODA

Characteristics of
Class Diplopoda:
 These are the millipedes
 Bodies usually round in
cross section
 2 pairs of legs per trunk
segment
 Slow moving
scavengers
 Some are equipped with
poison glands that
produce cyanides
The Kentucky flat millipede is
poisonous, but not venomous.
CLASS: CHILOPODA

Characteristics of
Class Chilopoda:
 These are the
centipedes
 Bodies usually flat in
cross section
 1 pair of legs per trunk
segment
 First pair of legs
modified into poison
claws (venomous)
 Fast-moving predators
The giant red-headed centipede is
the largest centipede in the Ozarks.
THE IMPORTANCE OF ARTHROPODS:
A LESSON IN ECOLOGY
Oak decline—villain bug, or a perfect storm?