Pests & Diseases

Insects - Anatomy Insects Small animals that have three body regions and three pairs or six legs. The three body regions are…. Head Thorax Abdomen

Parts of the Insect

Life Cycle of Insects Complete metamorphosis Egg Larva Pupa Adult Worm Caterpillar Pupa Adult Flies Beetles

Life Cycle of Insects Incomplete metamorphosis Egg Nymph Adult

Chewing Insects Beetle Eat leaves, stems, flowers, fruit and nuts.

Chewing Insects Cutworms Usually attack stems, but may eat other plant parts.

Chewing Insects Caterpillars Larva of moths and butterflies and are fuzzy or hairy. Eat young leaves and stems. Roll up in leaves making the leaves curl.

Grasshoppers Eat all parts of plants. Chewing Insects

Sucking Insects Aphids Pierce & suck juices. Known as plant lice. Cause stunted growth and yellow spotted leaves. Causes sticky substance and black mold which attracts ants.

Sucking Insects Mealybugs Pierce and suck from underside of leaves and in leaf axils. Causes yellow appearance and sticky secretions.

Sucking Insects Whiteflies Feed on underside of young leaves causing yellowing. They will look like flying little white specks when plants are shaken.

Plant Diseases

A plant disorder caused by an infectious pathogen or agent. What is a Disease???

Conditions Needed for a Disease Three conditions are necessary for a disease in a plant. Host plant Disease causing organism or pathogen must be present. Favorable environment for disease organism to develop.

The Disease Triangle

What Causes a Disease?? FUNGI The groups of pathogens are…. Bacteria Viruses Parasitic plants Mistletoe Dodder Lichens FUNGI

Parasitic Plants MISTLETOE DODDER LICHENS

Controlling Diseases Warm temperatures and moist conditions in greenhouse plant production make most horticulture plant diseases worse because…. Environmental conditions that support disease-causing pathogens. Preventing plant diseases is better than treating the diseases. Plant diseases must be identified before they can be treated.

Plant Diseases – Blight Cause plants to quickly turn brown as if they had been burned.

Plant Diseases – Canker Causes open wounds on woody plant stems.

Plant Diseases – Damping Off A fungal disease that causes young plants and seedlings to rot off at the soil level.

Round swellings or growths on plants. Plant Diseases – Galls

Plant Diseases – Leaf Spots Rings of different shades of brown, green, or yellow that make spots on leaves.

Plant Diseases – Mildew Grows on leaf surfaces (both upper & lower) as white, gray or purple spots.

Plant Diseases – Mosaic Caused by viruses that make the leaves have irregular mottled areas with patterns ranging from dark green to light green to yellow to white.

Plant Diseases – Rot Causes plants to decay & die.

Plant Diseases – Rust Causes small spots on leaves that resemble yellow, orange, brown or red rust mainly on the underneath side of leaves.

Plant Diseases – Smut A black powdery disease that causes blisters that burst open releasing black spores.

Plant Diseases – Wilts Disease that blocks the uptake of water in plants stems causing it to wilt.