Black Spot

Adrian Crabb* and Brian Hudelson, UW-Madison Plant Pathology *Completed for Plant Pathology 300 Revised:  8/13/2012 Item number:  XHT1089 What is black spot?  Black spot is a common and potentially serious leaf spot disease affecting many types of roses.  Black spot is found wherever roses are grown. What does black spot look like?  Black spot lesions […]

Mealybugs

Karen Delahaut, formerly UW-Madison Fresh Market Vegetable Program Revised:  4/26/2004 Item number:  XHT1129 Mealybugs are slow-moving, small, oval insects that are covered with a white, cottony wax.  They are tropical insects that are typically only found on perennial foliage plants, and rarely on flowering or bedding plants.  They can infest all plant parts including the […]

Scales

Karen Delahaut, formerly UW-Madison Fresh Market Vegetable Program Revised:  8/13/2012 Item number:  XHT1130 Scales are probably one of the most difficult insects to control because of their protective covering.  There are many species of scales, but they can all be categorized as either soft or armored.  Soft scales are tropical insects and are economically more […]

Two-Lined Chestnut Borer

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  8/13/2012 Item number:  XHT1155 The most important insect cause of oak mortality is the two-lined chestnut borer (Agrilus bilineatus).  This insect is attracted to stressed and weakened oaks.  Environmental extremes (e.g., drought), construction injury to roots, soil compaction, road salt injury, defoliation by leaf-feeding insects, storm damage and […]

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.

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 […]

Cicada Killer Wasps

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  1/4/2011 Item number:  XHT1198 Cicada killer wasps have become very common in the southern half of Wisconsin.  These solitary wasps are up to 1½ inches long, and their black and yellow coloring makes them look like giant yellow jackets. Life Cycle:  Adult cicada killer wasps appear from mid-July […]

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 […]

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 fall […]

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 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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