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 CutwormEuxoa 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 & HoneydewCoccus 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