See All Pest, Disease and Weed Identification

Ornamental plantings of holly in Pennsylvania are often damaged by leafmining pests. The native holly leafminer only feeds on the foliage of American holly.

A field day at one of Penn State Extension's Models for the Future sites reviewed the importance of a comprehensive disease management plan for your operation.

Varroa mites (Varroa destructor), are the most influential of all of the pests and diseases of the European honey bee (Apis mellifera) today.

Hickory tussock moth caterpillars are fuzzy, white and black caterpillars that are commonly encountered in the fall. The hairs are used for defense and may irritate the skin of sensitive individuals.

Grass spiders are common in Pennsylvania and can be recognized by their large, sheet-like webs with a funnel or tunnel located off to one side.

Araneus saevus is found from Canada into the northern United States. It can be seen in forested areas and suburbia with mature landscape plantings.

Camphor shoot borers are an introduced species of ambrosia beetle that attack small-diameter branches and trunks of stressed, weakened, and dying trees. They also accidentally bore holes into plastic gasoline containers, hoses, and tanks.

The false black widow is found in the coastal states of the Atlantic, Gulf, and Pacific regions. It is a common spider in homes and other structures.

Wolf spiders are large hunting spiders. Two notable species, Hogna carolinensis and H. aspersa, are occasionally encountered in Pennsylvania homes.

The jumping spiders are small, compact hunting spiders. Phidippus audax is the most common jumping spider seen in and around Pennsylvania homes.

The genus Araneus has about 1,500 species worldwide, making it the largest of all the spider genera.

This funnel weaver is found throughout most of the United States, most notably in sheds and barns, in the crevices of doors, and under rocks and boards.

The cross orbweaver was probably introduced from Europe. This showy orbweaver is commonly encountered next to buildings with exterior lighting.

The woodlouse hunter spider preys on pill bugs or sow bugs (order Isopoda) and derives its common name from the British common name for these crustaceans.

The southern black widow, L. mactans, is found in Pennsylvania. It is probable that the northern black widow, L. variolus, is also present.

Eleven species of Loxosceles are indigenous to the continental United States, four of which are known to be harmful to humans.

Stealthy ground spiders hunt at night and hide under leaves, boards, and stones during the day. The most commonly encountered of these is the parson spider.

Spiders are beneficial animals that feed on arthropods, including insects. Spiders rarely bite people, and most species found in the world are harmless.

Learn the distinguishing characteristics of the invasive tree-of-heaven that you can use to accurately identify it.

Flies in the family Syrphidae are helpful allies in the garden and in the greenhouse or nursery.

Poison-ivy (Toxicodendron radicans) is a native woody, perennial vine.

Turfgrass disease prevention and control programs on golf courses often include fungicide applications.

With soybean fields maturing, our final reports find very low pest activity.

Pest populations in soybeans remain low, but white mold is increasing in some places.

Pest populations in soybeans remain low, but white mold is increasing in some places.