Insect & Disease Index
Keystone’s arborists are very knowledgeable about insect and disease problems that may be affecting your trees and shrubs. In general, most insects and diseases are partial to a certain plant or tree. Many homeowners are afraid that these problems are going to “spread” to their other trees. This can be true for certain pests, such as Bagworm, but for the most part, specific insects and diseases tend to affect specific trees. This makes diagnosis fairly simple once the arborist identifies the plant. We then know which problems are apt to affect that particular tree or shrub. Effective treatment of plant problems is dependent on the insect’s or disease’s lifecycle. Treating at the wrong time will often be completely ineffective. Keystone monitors lifecycles during the year to assure that our treatments are timely and effective. On this section of our website, you will find information on the many insects and diseases that are prevalent in southeastern Pennsylvania.

- Ambrosia Beetles
- Aphids
- Apple Scab
- Bacterial Leaf Scorch
- Bagworm
- Box Tree Moth
- Black Knot Disease
- Boxwood Leafminer
- Cankerworm
- Cooley Spruce Gall Adelgid
- Cottony Scales
- Cytospora Canker of Spruce
- Eastern Tent Caterpillar
- Elongate Hemlock Scale
- Emerald Ash Borer
- European Pine Sawfly
- Gypsy Moth
- Hemlock Rust Mite
- Hemlock Woolly Adelgid
- Honeylocust Plant Bug
- Japanese Beetles
- Lace Bugs
- Mimosa Webworm
- Procera Root Disease of White Pine
- Rhabdocline Needlecast of Douglas Fir
- Spotted Lanternfly
- Spruce Spider Mite
- Stigmina Needle Cast
- White Pine Weevil