European Pine Sawfly, Neodiprion sertifer

If you’ve noticed masses or writhing, dark green “caterpillars” on your pine trees this spring, you likely have an infestation of European pine sawfly. This insect lives in large colonies, feeding on last year’s needles until they finish their development, then pupate in the soil or leaf litter. To learn more about this pest, read this article…

Zimmerman Pine Moth

Phil Pellitteri, UW Insect Diagnostic Lab, UW-Extension Revised:  8/13/2012 Item number:  XHT1164 Zimmerman pine moth (Dioryctria zimmermani) was first detected in the US in 1879, and has subsequently been found and is established throughout the northern US east of the Rocky Mountains.  Austrian and Scots pines are preferred hosts of Zimmerman pine moth.  However Eastern […]

Spruce Spider Mite

Phil Pellitteri, UW Insect Diagnostic Lab, UW-Extension Revised:  8/13/2012 Item number:  XHT1109 Spruce spider mites can attack a number of conifers including spruce, hemlock, white cedar (arborvitae), larch, and juniper. These mites go through four to six generations per year and populations can explode under warm, dry conditions. Spider mites feed by sucking on plant […]

Pine Root Collar Weevil

Vijai Pandian, UW-Extension Brown County and Phil Pellitteri, UW Insect Diagnostic Lab Revised:  8/13/2012 Item number:  XHT1183 Pine root collar weevil is a destructive pest of Austrian pine, Scots pine, red pine and more rarely Eastern white pine.  Young Austrian, Scots and red pines that are two to four inches in diameter at the soil […]

Ips Bark Beetle

Ips bark beetle, also known as the pine engraver, is an insect that attacks and kills weak, stressed, declining and dying pine and spruce trees. These insects are attracted to trees that have been stressed from drought, construction damage, overcrowding, transplant shock, flooding, disease and other insect problems. Identification and management are covered in this fact sheet.

Western Conifer Seed Bug

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  4/27/2004 Item number:  XHT1052 Western conifer seed bugs belong to the leaf-footed bug family Coreiidae.  Adults are 3∕4 of an inch long, elongate, reddish to dull brown with a faint, white zigzag straight line across the center of the wings.  They have long, thin antennae and hind legs […]

White Grubs on Christmas Trees

P.J. Liesch and R. Chris Williamson, UW-Entomology Revised:  5/20/2013 Item number:  XHT1208 White grubs (i.e., larvae) of the common May/June beetle or “Junebug” (Phyllophaga spp.) are an important pest of Christmas trees in Wisconsin.  This soil-dwelling pest feeds on the roots of pines, firs, and spruces, and can cause damage severe enough to kill small […]

Spongy Moth

P.J. Liesch, UW Entomology and R. Chris Williamson, formerly UW Entomology Revised:  4/1/2022 Item number:  XHT1063 The spongy moth, Lymantria dispar (formerly known as the “gypsy moth”) is native to parts of Europe, Asia, and North Africa. It was inadvertently introduced to North America in New England in 1869 and has since spread westward. Over […]

Aphids

Aphids are soft-bodied, sucking insects that are sometimes called plant lice. They feed on plant sap and subsequently excrete a sugary substance (called honeydew) that can attract ants as well as support the growth of a saprophytic fungus called sooty mold. Learn about common aphids found in home gardens in this factsheet.

Woody Ornamentals Pest Management in Wisconsin

Author(s): Chris Williamson, P.J. Liesch, Jim Kerns, Roger Flashinski Woody Ornamentals Pest Management in Wisconsin is an indispensable resource for nursery growers. This completely revised publication identifies pests of trees and shrubs in the state plus the products available for their control. It also notes products that are registered for use by homeowners (56 pages; […]

Aphids, in-depth

Aphids may be viewed as just another pest for gardeners to try to eliminate, but they’re really fascinating insects, with bizarre lifestyles and eating habits and they’re also dinner for lots of other insects. Forming colonies covering the leaves and stems of plants, these small sap-sucking creatures reproduce incredibly fast and a few also transmit plant diseases. Learn more about this large group of insects and how to manage them in the garden in this article…

Home Landscape Insecticides

Karen Delahaut, UW-Madison Fresh Market Vegetable Program Revised:  8/13/2012 Item number:  XHT1096 Recently, several commonly-used insecticides for the control of insects on woody landscape plants have been taken off the market.  As a result, it’s becoming ever more challenging for home gardeners to find suitable insecticide products at garden centers, discount stores, and hardware stores.  […]

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