InsectInteractions - Test
on
Wednesday
 • ...

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Unformatted text preview: Test
on
Wednesday
 •  Format
 –  35
mul3ple
choice
ques3ons
(2
pts.
ea.)
 –  3
short
answer
ques3ons
(10
pts.
ea.)
 •  How
to
study
 –  Last
year’s
exam
is
in
the
resources
folder
on
 bspace
 –  Review
lectures,
readings
and
handouts
 –  Email
ques3ons
to
me
or
the
readers
 Insects
and
their
interac3on
with
 plants
and
animals
 Insects
and
animals
 •  Zoophagous
and/or
carnivorous
insects
feed
on
 animals
or
their
products
for
nutri3on
 –  Predators
 –  Parasites
 –  Parasitoids
 –  Hematophagous
 –  Inquilines
 –  Social
parasites
 –  Scavengers
 –  Fungivores
 •  Predators
kill
and
consume
living
prey
 •  Predators
morphology
has
been
modified
over
 evolu3onary
3me
to
make
them
more
 efficient.
 –  Raptorial
modifica3ons
to
legs
 –  Modifica3ons
to
mouthparts
to
defeat
defenses
of
 other
animals
 hTp://www.youtube.com/watch?v=A9Q8gUTmyd8
 •  Parasites
live
in
close
associa3on
with
a
single
 host
without
killing
it.
 –  Sheep
bot
fly
 •  Adult
female
oviposits
in
nostrils
 •  Larvae
develop
in
the
head
sinuses
 •  Adult
then
migrates
out,
finds
a
mate
and
the
cycle
starts
 over
again
 Ovoviviparous:
females
don’t
lay
 eggs,
they
lay
first
instar
larvae
 Each
female
lays
~500
eggs,

 ~50
at
a
3me
 ~
60
species
of
bot
flies
in
the
genus
 Cuterebra
in
North
America.

Most
are
 parasites
on
rodents
 •  Human
bot
fly:
common
in
tropical
countries
 •  Life
cycle:
 –  Adult
female
captures
a
mosquito
and
glues
an
 egg
to
her
abdomen
 –  Heat
of
the
human
body
causes
the
eggs
to
hatch,
 releasing
the
larvae
onto
the
skin
 –  They
bore
into
the
skin,
develop
through
the
larval
 stages
to
pupa3on,
then
fall
out
of
the
wound
 (called
a
warble)
and
pupate
in
the
soil
 hTp://humanbobly.blogspot.com/2006/11/short‐documentry‐on‐bobly‐lifecycle.html
 If
you’re
squeamish…….
 
……..close
your
EYES!!!
 Human
head,
body
and
pubic
lice
 Preven&on:
Good
hygiene
 Treatment:
special
shampoos
and

 soaps,
nitpicker
 •  Parasitoids
live
in
close
associa3on
with
a
 single
host
that
is
slowly
consumed,
resul3ng
 in
death.
 Cluster
flies
are
parasitoids
of
earthworms
 Lepidoptera
larvae
are
oien
targets
for
 parasitoids
 •  Hematophagous
insects
are
obligatory
blood
 feeders.
 •  Inquilines
live
commensally
with
ants
or
 termites,
or
in
nests
of
various
animals.
 •  Scavengers
feed
on
waste,
droppings,
carcasses,
 and
exudates
in
various
stages
of
decay.
 Dung
beetles!
 •  Fungivorous
insects
require
fungal
frui3ng
 bodies,
hyphae
or
spores
for
food
 Insects
and
plants
 •  Phytophagy
or
herbivory:
Macera3on
of
plant
 3ssues
or
imbibing
plant
fluids
and
diges3ng
 them
for
their
nutri3onal
value.
 –  Insects
obtain
sugars,
fats,
salts,
vitamins,
and
 water
 –  Insects
have
a
limited
ability
to
digest
cellulose,
a
 major
component
of
most
plant
cells;
many
have
 coevolved
with
endosymbionts
to
help
digest
this
 •  Oldest
insect‐plant
associa3on
is
from
~300my
 old
fossils
 •  Insects
and
plants
both
began
to
rapidly
 diversify
~150my
ago
 •  Pollina3on:
Plant
pollinators
are
responsible
 for
a
large
por3on
of
US
agricultural
ac3vity

 –  >
$3
billion
annually
 •  Pollina3on
involves
a
long‐term
coevolu3on
 (~150‐200
million
years)
 –  Early
plants
were
wind
pollinated
 –  The
first
insect
pollina3on
was
likely
uninten3onal,
 a
herbivorous
insect
transferred
some
pollen
 accidentally
 –  Insects
have
since
evolved
many
structures
that
 allow
them
to
more
efficiently
move
pollen
from
 place
to
place
 •  Insects
move
plant
gametes
from
place
to
 place,
either
in
exchange
for
some
reward
 (nectar)
or
because
of
trickery
 •  Many
plants
en3rely
depend
on
insects
for
 reproduc3on.

Many
insects
cannot
live
 without
their
host
plants
 •  Plants
aTract
insects
with
 –  Color,
including
UV
reflectance
 –  Odors
associated
with
food,
females
or
alarm
 –  Visual
display
that
mimics
female
insects
 Insect
Pests
in
Agriculture
and
Forestry
 Corn
>300
pests
 Citrus
>200
pests
 Apples
>400
pests
 Oak
>1500
pests
 General
Categories
of
Insect
Feeding
 •  Monophagous:
specific
to
a
single
type
of
plant
(ex:
 many
Lepidoptera)
 •  Oligophagous:
will
use
a
few
similar
or
related
plants
 (ex:
monarch
bu7erfly
uses
many
species
of
milkweeds;
 Colorado
potato
beetle
uses
several
members
of
the
genus
 Solanum)
 General
Categories
of
Insect
Feeding
 •  Monophagous:
specific
to
a
single
type
of
plant
(ex:
 many
Lepidoptera)
 •  Oligophagous:
will
use
a
few
similar
or
related
plants
 (ex:
monarch
bu7erfly
uses
many
species
of
milkweeds;
 Colorado
potato
beetle
uses
several
members
of
the
genus
 Solanum)
 •  Polyphagous:
will
use
a
wide
variety
of
plants
(ex:
 most
Orthoptera;
hungry
locusts
will
eat
fence
posts,
crickets
 will
eat
clothing)
 Types
of
Damage
 •  Direct:
chewing,
sucking,
gall
inducing
 –  –  –  –  CosmeBc
 ReducBon
of
yield

 Death
 Phytotoxenia
(reacBon
to
insect
saliva)
 •  Indirect:
disease
vectoring
 –  Viruses
(Le7uce
Mosaic
Virus)
 –  Bacteria
(Pierce’s
Disease)
 –  Fungi
(Dutch
Elm
Disease)
 Pierce’s
Disease
 How
insects
find
their
host
plants
 •  Search
out
specific
habitats
 •  Locate
a
plant
and
find
a
suitable
part
for
feeding
or
 eggs
 •  Ini3ate
feeding
(taste)
 •  Feed
to
sa3a3on
 Interrup3on
of
any
of
these
steps
can
lead
to
a
reduc3on
in
 insect
feeding
damage
and
an
increase
in
crop
yield
 Plant
Defenses
 •  Non‐aTrac3ve:
don’t
taste
par3cularly
good,
don’t
 have
strong
aTractant
quali3es
 •  An3biosis:
reduce
feeding,
reproduc3on,
growth
 –  Chemical
–
repellants,
anBfeedants,
toxins,
growth
regulators,
 proteinase
inhibitors
 –  Physical
–
Tough
cellulose
covering
dense
hairs

 –  Ecological
–
alter
Bming
of
life
cycle
(phenology),
spaBal
distribuBon
 (sca7ered
or
isolated
plants)
 •  Tolerance:
herbivory
has
liTle
or
no
effect
 Insect
Coevolu3on
 •  Evolve
biochemical
pathways
(or
microbial
 associa3on)
to
detoxify
or
avoid
plant
chemicals
 •  Synchronize
life
history
with
plant
 •  Evolve
behaviors
or
morphological
structures
that
 counter
physical
defenses
 ...
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This note was uploaded on 09/18/2010 for the course ESPM 28981 taught by Professor O'grady during the Fall '10 term at University of California, Berkeley.

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