Leaf Color Change in Autumn

The bright yellow, orange and red colors of autumn leaves are one of nature’s most beautiful spectacles. Although a familiar annual event, much of our understanding of autumn leaf coloration has, until recently, been based primarily on random observation and speculation.

Dodder

Jennifer Clifford, Amilcar Sanchez, Trenton Stanger, and Brian Hudelson,UW-Madison Plant Pathology Revised:  10/21/2006 Item number:  XHT1156 What is dodder?  Dodder is the name of several species of parasitic plants that are widely distributed in North America and Europe.  Plants parasitized by dodder include alfalfa, carrots, onions, potatoes, cranberries, a variety of herbaceous and woody ornamentals, […]

Reducing Soil pH

Sherry Combs, formerly of the UW-Madison Soil and Plant Analysis Lab Revised:  10/27/2007 Item number:  XHT1151 Is your soil pH too high?  Probably not, although the popular press urges most gardeners to question whether their garden soil pH is ‘right’.  Only a soil test for pH can indicate whether the pH is ‘right’, and ‘right […]

Dead Man’s Fingers

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  8/13/2012 Item number:  XHT1201 What is dead man’s fingers?  Dead man’s fingers is the name of a mushroom-like fungal growth that can be found at the base of dead or dying trees and shrubs, as well as wood objects (e.g., wood barrels) that are in contact […]

Four-Lined Plant Bug

Carla Staab*, Milwaukee Area Technical College, and Phil Pellitteri, UW Insect Diagnostic Lab ompleted as partial fulfillment of the requirements for an associate degree in Horticulture at the Milwaukee Area Technical College. Revised:  4/27/2004 Item number:  XHT1101 The adult four-lined plant bug (Poecalocapsus linectus) is a 1∕2 inch long, yellowish to yellowish-green true bug with […]

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 […]

Webworms

R. Chris Williamson, UW-Extension Turf and Ornamental Specialist Revised:  4/25/2004 Item number:  XHT1066   The term webworm is used to describe several insects whose caterpillars use silk to join plant parts together to form protective nests.  Two common insects that create nests in fruit and woody ornamental trees are the eastern tent caterpillar and the […]

Pear Slug (Pear Sawfly)

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  12/30/2010 Item number:  XHT1200 Pear slugs are not true slugs (see University of Wisconsin Garden Facts XHT1040), but are larvae of the pear sawfly (Calora cerasi). These larvae feed and cause damage on many kinds of ornamentals and fruit trees, including cherry, cotoneaster, mountain-ash, pear, purple leaf plum […]

Degree Day Calculation

Karen Delahaut, UW-Madison Fresh Market Vegetable Program Revised:  8/6/2012 Item number:  XHT1086 Indicator plants are not always suitable for the timing of pest management practices.  You may not have the critical indicator plant  nearby to time local activities, or there may not be a good indicator plant for a particular pest’s crucial life stage.  Another […]

Phenology

Karen Delahaut, UW-Madison Fresh Market Vegetable Program Revised:  5/17/2012 Item number:  XHT1085 The word phenology is derived from the Greek word phaino meaning “to show” or “to appear”.  Phenology is a branch of science that studies the relationships between periodic biological events—usually the life cycles of plants and animals—and environmental changes.  Natural events such as […]

Degree Days for Common Landscape Insect Pests

Karen Delahaut, UW-Madison Fresh Market Vegetable Program Revised:  8/13/2012 Item number:  XHT1088 Ash Borer 1st instar larvae = 275-500 DD50 Ash Plantbug Nymphs = 100-200 DD50 Birch Leafminer 1st generation larvae = 275-500 DD50 Black Vine Weevil 1st generation adults = 400-600 DD50 2nd generation adults = 900-1000 DD50 Bronze Birch Borer Larvae = 400-500 […]

Cicadas

R. Chris Williamson, UW-Extension Turf and Ornamental Specialist Revised:  8/13/2012 Item number:  XHT1068 Adult periodical cicadas (Magicicada spp.) are black and have reddish-orange eyes and legs, and have clear wings with orange veins that are positioned over their bodies like a roof or canopy.  Male cicadas typically make a loud buzzing noise or squawk when […]

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