Nursery Landscape Disorder Study Guide Central Region Ag Education

All of the following insects should be treated by an insecticide

Aphids Always appear in large groups, can be many different colors and sizes Produces a sap (honeydew) that promote the growth of sooty mold (seen above) Can also cause leaf curling/ distortion on new growth

Bagworm An insect that attacks arborvitae, juniper, pine, spruce, and many other evergreen species. This insect is most easily recognized by the case or bag that the caterpillar forms and suspends from ornamental plants on which it feeds. The bag is made of silk and bits of host foliage.

Borer Borer insects can be many different colors and sizes. Typically has a hard body Borer leaves very distinctive tunnels inside the tree

Grub White in color Legs only on front end of body Naturally “C” Shaped

Leafminer mining damage Leafminer larvae Leafminer mining damage Leafminer adult

Mealy Bugs Always white in color, start off in small groups The webbing around some is the female laying eggs or an already formed egg mass

Scale Scale can be found on the stems of the plant and the underside of the leaves. Scale can be several different colors. Scale can also be flat bodied and sit very close to the plant or sit more raised up on the surface. Hard bodied scale Soft bodied scale

Are normally found on the underside of the leaf Whitefly Whiteflies are small, white, winged insects. Are normally found on the underside of the leaf Lay eggs on the bottom of leaves, often egg castings( remains) are still visible even after they have hatched

All of the following insects should be treated by an miticide Mites All of the following insects should be treated by an miticide

Spider Mites appear in large groups and adults have 8 legs Notice speckling on the leaves from spider mite damage Also produce webbing in-between leaves of plant

All of the following pests should be treated by an mulluscicide bait Mollusc All of the following pests should be treated by an mulluscicide bait

Slug Unsegmented, soft, and slimy body – does not have a shell Slug damage

All of the following pests should be treated by an fungicide Fungus/ Molds All of the following pests should be treated by an fungicide

Black Spot Brown or black circular or angular areas of dead tissue. Often dry

Powdery Mildew Mold that is white/gray in color Flat mold that grows along the top surface of the leaf

Other Disorders

Easy to identify by the remaining green veins with yellowing tissue Iron Chlorosis Caused by Iron Deficiency Loss of green color of chlorophyllous tissue Occurs first on new growth

All of the following pests should be treated by an herbicides Weeds All of the following pests should be treated by an herbicides

Grows flat along the ground, much like a “carpet” pattern Very noticeable hairy sheath around the leaf, Crab Grass Hairy on the sheth of the grass, widest leave blade of the three grasses on the disorder list Thicker blade, clump like growth Grows flat along the ground, much like a “carpet” pattern

Annual Bluegrass dense, low clumps, 3 to 12 inches tall. Leaf blades are hairless, often yellowish green, and sometimes dark green. They are often crinkled at the midsection

Plaintain The leaves are oval with a long, broad petiole. The leaf blade is 4 to 10 inches long with smooth edges. The flower-spikes, erect, on long stalks, are as long as the leaves, 1/4 to 1/3 inch thick and usually blunt.

Chickweed Usually sprawl across the ground. The somewhat succulent stems are green or burgundy; they often have lines of white hairs. Pairs of opposite leaves occur at intervals along these stems. These leaves become larger toward the tips of the stems. The leaves are oval-ovate, entire (toothless) along their margins, and hairless on the upper surface; the lower surface is occasionally hairy.

Clover Branching stems grow between 4 to 12 long and creep along the ground. Leaves alternate with one another along the stem and consist of three leaflets. Each leaflet is 1/4 to 1/2 of an inch long, nearly hairless and may have a whitish crescent in the center.

Dandelion The plants are as short as 2” but can also be as tall as 18”.  The leaves are typically thin, deep green and coarsely toothed. The shiny and hairless leaves are clustered, growing from plant base in spreading rosette. The long, thick taproot typically goes straight down. The flower is bright yellow to orange in color. The flower ultimately turns into a white ball of seed heads.

Henbit greenish to purplish, tender, square stems. Leaves directly attached to the stem. Can grow to a height of 16 inches. Flowers are reddish purple in color with darker coloring in spots on lower petals. Flowers arranged in whorls in the upper leaves.

Purslane Spreading growth pattern, up to 3-1/3 ft in length, and has many succulent branches, starting from the base. Leaves are egg to spatula shaped, succulent, stalkless or have very short stalks, about 1/5 inches to 1-1/5 long, and sometimes their edges are red-tinged. Leaves are arranged either opposite one another or alternate along the stem.

Wild Garlic/Onion thin, green, waxy leaves, those of wild garlic are round and hollow, while those of wild onion are flat and solid. Very distinct onion/ garlic smell

Nut Grass Has “nuts” that grow on the roots of the plant Has a very pronounced midrib Thicker leaf blade, Grows vertical, not horizontal

Oxalis Heart shape leaf Looks similar to clover but smaller Flowers are usually yellow but can also be purple