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Spotted lanternfly on apple in Berks County, PA in October 2017. Photo: Erica Smyers, Penn State
Spotted Lanternfly on Grapes and Tree Fruit - Articles Articles

Spotted Lanternfly on Grapes and Tree Fruit

Julie Urban, Dave Biddinger, Ph.D., Ed Rajotte, Ph.D.

Biology, management and slowing the spread of the spotted lanternfly on grapes and tree fruit in the Mid-Atlantic Region. More
Pitch mass, a symptom of Zimmerman pine moth, located at the junction of a lateral branch and main stem. Courtesy of Whitney Cranshaw, Colorado State University, (#1325082)
Zimmerman Pine Moth - Articles Articles

Zimmerman Pine Moth

Ed Rajotte, Ph.D.

Field identification is usually through the presence of a popcornlike pitch mass on the main trunk. Damage includes reddish, sawdustlike frass at bore holes. More
Typical “shepherd’s crook” symptomatic of white pine weevil infestation. Courtesy of PDA
White Pine Weevils - Articles Articles

White Pine Weevils

Ed Rajotte, Ph.D.

White pine weevil adults have long snouts and elbowed antenna with terminal knobs. Damage includes a typical "shepherd's crook" wilt. More
Damage from deer to a Scots pine. Courtesy of Jan Liska, Forestry and Game Management Research Institute, (#2113036)
Vertebrate Pests of Christmas Trees - Articles Articles
Birds tend not to be a big problem associated with Christmas tree production, but damage occasionally occurs to the tops, particularly of taller trees. More
Elliptical cankers covered with yellow blisters that release infectious spores to be carried away by the wind. Courtesy of Tracey Olson, PDA
White Pine Blister Rust - Articles Articles

White Pine Blister Rust

Ed Rajotte, Ph.D.

A small, yellow or red spot appears on the needle at the site of infection and the needle may die as the fungus grows into the bark. Damage shows up as dead or dying branches. More
White grub damage to seedlings. Courtesy of Jim Stimmel, PDA
White Grubs (May, June and Japanese Beetles) - Articles Articles
Larvae of white grubs feed on roots of conifer seedlings and transplants. Damage includes seedling discoloration (reddish brown) in late summer to early fall. More
Swiss Needle Cast
Swiss Needle Cast - Articles Articles

Swiss Needle Cast

Ed Rajotte, Ph.D.

Symptoms are present on Douglas fir needles within 3 years of infection. The fruiting bodies can be seen with a hand lens. Damage includes dieback of needle tips resembling drought damage. More
Severe scale crawler infestation on Scotch pine, along with a heavy amount of sooty mold (black coating on stem and needles). Courtesy of Brian Schildt, PDA
Striped Pine Scale - Articles Articles

Striped Pine Scale

Ed Rajotte, Ph.D.

The coverings of adult female scales resemble miniature helmets. They are reddish brown and may have cream or white stripes. Damage may show as black sooty mold. More
Spruce spider mite feeding damage. Courtesy of Eric R. Day, Virginia Tech, (#0717020)
Spruce Spider Mites - Articles Articles

Spruce Spider Mites

Ed Rajotte, Ph.D.

Spruce spider mites can develop from an egg to an adult in 2–3 weeks under normal conditions. Damage includes small, irregularly shaped yellow spots (“stippling”) on needles. More
Yellow bands containing faint orange fruiting bodies distinctive of spruce needle rust. Courtesy of Tracey Olson, PDA
Spruce Needle Rust - Articles Articles

Spruce Needle Rust

Ed Rajotte, Ph.D.

Infected trees may appear disfigured and have extensive needle discoloration, reduced growth, and premature needle drop. Damage will show as pale yellow bands that go completely around the needle. More
Rhizosphaera-infected foliage on inner branches and lower parts of the tree. Courtesy of USDA Forest Service North Central Research Station Archive, (#1406191)
Rhizosphaera Needle Cast - Articles Articles

Rhizosphaera Needle Cast

Ed Rajotte, Ph.D.

Young trees sustain the most severe damage from rhizosphaera needle cast, but trees of any size can be affected. Damage causes discoloration of needles. More
Foliage with Rhabdocline needle cast infection. Courtesy of Tracey Olson, PDA
Rhabdocline Needle Cast - Articles Articles

Rhabdocline Needle Cast

Ed Rajotte, Ph.D.

This infection occurs around bud break, when buds are opening to expose susceptible immature needles. Damage shows up as yellow spots or flecks that enlarge with time. More
Girdling lesions banding the needle. Courtesy of Tracey Olson, PDA
Red-Band (Dothistroma) Needle Blight - Articles Articles
Red-band needle blight occurs throughout the growing season during wet periods. Initial symptoms include dark green bands on the needles, quickly replaced with brown or reddish-brown lesions. More
Symptoms of needles infected with Ploioderma needle cast. Courtesy of Tracey Olson, PDA
Ploioderma Needle Cast - Articles Articles

Ploioderma Needle Cast

Ed Rajotte, Ph.D.

Although Ploioderma needle cast occurs in spring, symptoms are not apparent until winter when yellow spots and bands appear, giving the needles a mottled appearance. More
Dead tree with reddish-brown needles still attached. Courtesy of A. Steven Munson, USDA Forest Service, (#1470133)
Pine Wilt Disease - Articles Articles

Pine Wilt Disease

Ed Rajotte, Ph.D.

Pinewood nematodes spread from infected to healthy pines in the spring through contaminated pine sawyer beetles. Needles turn yellow then reddish brown. More
Flagging damage from pine shoot beetle. Courtesy of Rayanne D. Lehman, PDA
Pine Shoot Beetle - Articles Articles

Pine Shoot Beetle

Ed Rajotte, Ph.D.

Although they can survive as mature larvae or pupae, pine shoot beetles most often overwinter as adults in the bark or lower stems at the base of trees. Damage includes shoot and branch injury More
Feeding damage from European pine sawfly. Courtesy of Sandy Gardosik, PDA
Pine Sawflies - Articles Articles

Pine Sawflies

Ed Rajotte, Ph.D.

Pine sawfly larvae are caterpillar-like with six or more pairs of prolegs on the abdomen. Larvae use their chewing mouthparts to consume entire needles, which can result in extensive defoliation. More
Dying tree with pine root collar weevil infestation. Courtesy of Sandy Gardosik, PDA
Pine Root Collar Weevil - Articles Articles

Pine Root Collar Weevil

Ed Rajotte, Ph.D.

To locate larvae, remove soil down to the first root flare. Damage includes trees loose in soil, leaning or dying (entire trees may be yellowed). More
White flecks on Scotch pine needles (signs of a pine needle scale infestation). Courtesy of Cathy Thomas, PDA
Pine Needle Scales - Articles Articles

Pine Needle Scales

Ed Rajotte, Ph.D.

Pine needle scale is an armored scale that produces a white, oyster-shell-shaped, wax covering. Damage is seen as white flecks on needles or white oyster-shell-shaped scales. More
Tree with pine bark adelgid infestation on the branches and trunk. Courtesy of Brian Schildt, PDA
Pine Bark Adelgid - Articles Articles

Pine Bark Adelgid

Ed Rajotte, Ph.D.

Pine bark adelgids overwinter predominately as immature females. By early spring, the mature female begins to produce a coating of woolly wax. Damage includes shoot and branch injury. More
Severe tree browning, a symptom of Phytophthora root rot. Courtesy of Tracey Olson, PDA
Phytophthora Root Rot - Articles Articles

Phytophthora Root Rot

Ed Rajotte, Ph.D.

Trees that do not thrive after planting or quickly develop reddish-brown needles and exhibit dieback should be checked for Phytophthora. More
Flagged branches are a symptom of pales weevil feeding. Courtesy of Sandy Gardosik, PDA
Pales Weevil - Articles Articles

Pales Weevil

Ed Rajotte, Ph.D.

Pales weevils overwinter as adults in the soil and become active between April and June. Damage includes shoot and branch injury. More
J-root planting damage on Virginia Pine. Courtesy of Bill Murray, University of Georgia, (#0485015)
Mechanical Damage to Christmas Trees - Articles Articles
Growing Christmas trees requires the use of many different types of equipment and tools. If not properly used, these may actually damage the trees. More
Lophodermium needle cast, the “spring reddener,” infection on a field of pine. Courtesy of Edward L. Barnard, Florida Department of Agriculture and Consumer Services, Bugwood.or (#4823057)
Lophodermium Needle Cast - Articles Articles

Lophodermium Needle Cast

Ed Rajotte, Ph.D.

Needle infection starts in mid- to late summer and only the current year’s growth is susceptible. Damage includes needle discoloration and injury. More
Scouting. Courtesy of Cathy Thomas, PDA
IPM for Christmas Trees: Seasonal Monitoring Guide - Articles Articles
A good scouting program for your Christmas tree farm can lead to a more accurate pest and disease control program. More
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