See All Pest, Disease and Weed Identification

Powdery mildew is usually first noticed on the leaves, but can also affect the fruit.

Anthracnose, caused by species in the genus Colletotrichum, can manifest as a fruit rot, crown rot, and/or leaf spots, as well as lesions on petioles and runners.

Black root rot a "disease complex," meaning that it can be caused by various pathogens combined with environmental stresses.

The 1/2-inch-long copper and green adult Japanese beetle, Popillia japonica (Newman), may appear in large numbers at harvest in late June to feed on the leaves.

Advice for collecting a good plant or insect sample for identification.

Crown and cane gall are bacterial diseases with no cure that constrain plant vigor and can cause plant death.

Powdery mildew, a warm-weather high-humidity disease, appears occasionally in blueberry plantings. Lowbush, highbush, and rabbiteye blueberries can be affected.

Verticillium wilt is caused by two common soilborne fungi (Verticillium dahliae and Verticillium albo-atrum) that have a wide host range and attack more than 300 woody and herbaceous plants.

Tree-of-heaven is especially difficult to eliminate. Learn when and how to apply control measures, including herbicides, to eradicate this prolific tree.

Learn the identification characteristics of the invasive tree-of-heaven and be able to distinguish it from the native look-alikes, black walnut and staghorn sumac.

Botrytis bunch rot, or gray mold, is commonly associated with the decay of ripe or nearly ripe grapes. Cool temperatures and damp conditions favor disease development.

Botrytis blight and fruit rot of blueberry, caused by Botrytis cinerea, is most common if the weather is wet and rainy during bloom.

Sooty blotch and flyspeck of apple are separate diseases affecting apple, crabapple, and pear trees. Oftentimes, both diseases are present on the same fruit.

The San Jose scale, once established, can be difficult and expensive to control.

The rosy apple aphid, Dysaphis plantaginea, has been a major pest of apple trees, causing both direct and indirect injury since the end of the nineteenth century.

Climatic irregularities govern the activities of the plum curculio, Conotrachelus nenuphar, a pest injurious to pome and stone fruits throughout the state.

Lesser peachtree borer is almost always associated with widespread incidence of Cytospora canker and, to a much lesser extent, pruning wounds, winter injury, and mechanical damage.

The Japanese beetle, Popillia japonica, is often the most important pest of tree-ripened peaches and can cause severe damage to other important crops.

The green peach aphid, Myzus persicae, is a common pest of peaches in Pennsylvania. Peach trees are its primary host and overwintering source.

Slugs can eat virtually all crops and inflict most of their damage during crop establishment and early growth in the spring and fall.

In Pennsylvania field crops, black cutworm is most often a pest of corn, but can also cause trouble in wheat and tobacco.

Alfalfa weevil is one of the two most-damaging insect pests of alfalfa in Pennsylvania (the other is potato leafhopper). It is an exotic species that likely evolved in Asia, but appears to have been introduced to the U.S. at least three times.

Have you noticed a decline in yield without a clear explanation? It could be due to plant parasitic nematodes.

La polilla del boj (Cydalima perspectalis) es un insecto invasor nativo del este de Asia que desfolia las plantas de boj (Buxus spp.) lo que debilita los arbustos y puede provocar su muerte.

Propagating plants means to create new plants by both sexual (seeds) and asexual (vegetative) means.