Arthropod Identification (01/12) Part 1

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Biodiversity – An
introduction to the world,
largely represented by
insects…
Larry Dapsis
Cape Cod Cooperative
Extension
www.capecodextension.org
Insects are the predominant multi-cellular life form on Earth…successfully
occupying numerous niches in terrestrial ecosystems. There are about a
million named species…collections, particularly in rain forests suggest that
the true number could be 10 million or more.
Insect Orders
31 classified “buckets”
This deck will cover most of these
buckets…I left out the embioptera and
zoraptora mostly because they are not
found in the northern U.S., as well as
the protura…since they are rarely
collected…and strepsiptera, insect
endoparasites rarely seen.
Qualifier: should any of your students
find any of these in Massachusetts,
tell them that they will be propelled
into entomological history…my
contacts at the Smithsonian will be
the final judge, so nobody should
have a friend down south mail some…
Systematics…how we classify
organisms…developing and understanding
relationships
Systematists evaluate
groups of organisms
and look for common
as well as divergent
characteristics. The
“junk” project is a
good way to learn
this…what traits are
ancestral or derived.
I did this in grad
school with 8
colleagues…we came
up with 9 similar, but
different keys (hotly
debated…the norm in
science and sports…)
Classify based on common characteristics…Judgement
calls as some systematists tend to be ”lumpers or
splitters”…and things change based on new evidence.
Cockroaches and Mantids
used to be part of the
Orthoptera, grasshoppers
and such.
Lice now are in one order but
used to be in two,
Mallophaga and Anoplura…
Arthropod Systematics…work in progress
Insects are very
diverse and dominate
terrestrial
ecosystems…their
counterparts, the
Crustacea dominate
saltwater systems.
That said, there are
still about 1,000
insects species in
saltwater habitats.
This may seem like a
lot, but considering
that there are about
5,500 species of
mammals (25% of
which are
represented by bats)
Wolbachia Project has a
morphospecies key…to
aid in the accurate
classification of
samples to insect
orders
…find out what
universities
maintain an insect
collection and visit
one…it will blow
you away…
Insect morphology
Use of the
morphospecies key
requires knowledge
of some basic
morphology. Insects
are comprised of
three major
areas…head, thorax
where wings and
legs attach, and an
abdomen.
Characteristics such
as antennae, wings
and mouthparts
show tremendous
variations on this
basic theme.
Wolbachia Project
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This deck is an overall guide to the id of insect orders…I
hope that you find it useful and at the same time
interesting…
The research that you are engaging has one small
requirement, adult stage insects
So arthropod creatures like worker ants and grasshoppers
without fully developed wings will not work out
If you have any questions about what works and what does
not just contact me at ldapsis@barnstablecounty.org
I strongly recommend that you check out
www.capecodextension.org the natural resources page…I
put together a guide for the prevention of tick-borne
diseases. These are very serious but, entirely
preventable…get your gameplan together and enjoy your
expeditions. Understand your environment, do not fear
it…ld
A visual tour of insect
diversity begins with a look
at this very primitive group.
Small…and can be seen in
the winter jumping on
snow…very cool to observe.
These to the right have the
common name of snow
fleas…
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Order Collembola Springtails
A furcula is a
distinguishing
characteristic. This
“springloaded”
appendage allows
them to jump 7 or 8
inches.
Ecologically
important as
“recyclers”. Very
numerous in soil and
leaf litter.
Considered by some
the have the
greatest collective
biomass on the
planet!
6 mm or
less…i.e. little
creatures
The 7 inch
jump of a
springtail
would be the
equivalent of a
person doing a
backflip over
the Eiffel
Tower…pretty
impressive
biomechanics
going on…do
not try this
1,063 feet
http://www.youtube.com/watch?v=OwOL-MHcQ1w
Check out this way cool BBC piece on springtails…
Order Diptera - Flies
Characterized by
one pair of wings.
Note a second pair
of appendages
behind the wings,
halteres.
You can observe
that these vibrate
like wings. This is
an inertial guidance
system that
stabilizes the
creature during
flight.
If Halteres are in
front…not a
fly…Strepsiptera.
Internal parasites of
insects…not very
common
Order Diptera Flies
Mouthparts can be spongy (left) or
modified into a tube (above) as on a
mosquito. Note mosquito antennae
are feathery while many flies have
them highly reduced (left). Eyes
tend to be large.
Not Wasps or Bees….Order
Diptera – Flies…one pair of
wings…Mimicry is reflected
in a number of insect
orders. In this case it can
be helpful to look like
something you just do not
want to interact with…
Eyes can be
the dominant
part of the
head, as
below….
Eyes can also make
you look a little
mean like this
horsefly…and, they
have the attitude to
back it up…
Eye diversity to the max!
This is a stalkeyed fly.
They are predominantly
found in Old World
tropical habitats but
there are two North
American species.
Recent research has
found that this is a
sexual selection
characteristic…males
with wider eyes seem to
be more successful at
finding a mate, really!
Order Lepidoptera – Butterflies, Moths and
Skippers
Large winged with respect to body
size. Antennae can be feathered as
in this cecropia moth (above) or thin
with a club as in this monarch (upper
right), our National Insect.
Mouthparts are usually long and
coiled.
NOTE: June 25 – July 1, 2012 is
National Insect Week
Lep mouthpart bonus slide…it has a coiled mouthpart but, it has really
hard hairs at the end. Instead of collecting nectar and such, it will
abrade your skin to blister capillaries for a blood meal…meet the
vampire moth, southeast Asia…another example of adaptation and
exploitation of a niche. Looks like this line evolved from a group that
specialized in feeding on secretions around eyes…they just kicked it
up a notch…very cool.
Wing Scales
Wings are covered with
scales…an individual scale is to
the right…it’s a diffraction
grating. Color is produced by
an effect known as Quantified
Interference and Diffraction.
This effect can produce nearly metallic coloration. Metallic looking
beetles use the same optical physics trick (in addition to
hummingbirds and peacocks…)
Say no more…very striking…
Many moths appear
relatively drab.
They are largely
nocturnal and rest
during the day…this
type of cryptic
appearance make
them less likely to
be seen by
predators like birds.
But birds have
excellent vision so
looking drab is not
the total solution
for survival…
This is an underwing moth, a member of the family
Noctuidae. If they are alerted to a predator the front wings
open quickly revealing highly colored hind wings, which
may even look like eyespots. This “flash” can momentarily
startle a potential predator giving the moth time to get
away…this is way incredible.
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