Transcript Entomology - Symptoms - Modesto Junior College

ENTOMOLOGY – SYMPTOMS
CHEWING
Chew off external parts of a plant
 Grind them up
 Swallow solids and liquid parts together
 Grazing

CHEWING
Cabbageworms
 Armyworms
 Grasshoppers
 Colorado potato
beetle
 Pear slug (sawfly)
 cankerworm

Pear Sawfly
CABBAGEWORM
ARTOGEIA RAPAE
ARMY CUTWORM
EUXOA AUXILIARIS
CLEARWING GRASSHOPPER
PEAR SLUG CALIROA CRASEI
PIERCING-SUCKING
Piercing the epidermis and sucking out the sap
from the cells within
 Internal and liquid portions of the plant are
swallowed
 Insects remains on the plant

PIERCING-SUCKING
Have an extremely slender and sharp pointed
portion of the beak
 Thrust into the plant
 Sap is sucked

PIERCING –SUCKING EFFECT

Minute spotting or white, brown or red
 Leaves
 Fruit
 Twigs
Curling of the leaves
 Deformed fruit
 Wilting, browning and dying

PIERCING - SUCKING
Aphids,
 Scale insects
 Leafhoppers
 Squash bug
 Plant bug

APHIDS
APHID CURLING & DISTORTION
APHIDS ON GERANIUM
BROWN SCALE & HONEYDEW
COCCUS HESPERIDUM
LEAFHOPPER
POTATO
LEAFHOPPER
DAMAGE
SQUASH BUG
INTERNAL FEEDERS
Feed within the plant tissues a part of all of
their destructive stages
 Gain entrance by having eggs deposited into
the tissues
 Eating their way in once the eggs hatch
 Hole is very minute (invisable)
 Large hole indicates the exit of the insect

INTERNAL FEEDERS
Borers
 Worms
 Leaf miners
 Gall insects

ASH BORER
LEAF MINERS

Small enough to feed between the upper
and lower epidermis of a leaf
GALL INSECTS
Sting the plant which then grows a home for
them
 Insects find shelter and food inside the gall
 Development from the secretions of the larvae
 Different insects on same plant make different
structured galls

Cooley Spruce Gall
CHOKECHERRY MIDGE IN GALL
SUBTERRANEAN INSECTS

Attack roots and underground stems
SUBTERRANEAN INSECTS








Chewers
Sap Suckers
Root borers
Gall insects
Woolly apple aphid
Wireworms
Root maggots
Billbugs
LAYING EGGS


Puncture tissue as a place to lay eggs
Cicada places eggs in 1 year twigs – splitting
the wood
Buffalo Tree Hopper
USE OF PLANTS FOR MAKING NEST

Leaf-cutter bees
 Take
a semicircular
piece of rose and other
foliage
 Cemented together to
form thimble-shaped
cells
 In a tunnel made in the
stem of a plant
CARRY OTHER INSECTS TO THE PLANT AND
ESTABLISHING THEM THERE
INSECTS VECTOR PATHOGENS
Feed, lay eggs, or bore into plants Making an
entrance point for disease
 Move pathogen on their bodies from one plant
to a susceptible surface of another plant
 Carry pathogens on the outside or inside of
their bodies and inject them as they feed

INSECTS VECTOR PATHOGENS
Pathogens can spend time in the bodies of
insects, can overwinter their
 Insects act as a host for a pathogen

VECTORED PATHOGENS
Dutch Elm Disease
(fungus)
Small Beetle
Fireblight (Bacteria)
Pollinating Insects
Tomato Curly Top (virus) Beet Leafhopper
Cucumber Mosaic (virus) Aphids