Invasive Pest and Horticulture issues

      The Harlequin Bug

The harlequin bug is a serious pest of cole crops in the souther US. "Cole crops" is a general term used to describe several vegetables in the mustard family, including broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale and kohlrabi. In the absence of their favorite hosts, this pest also feeds on tomato, potato, eggplant and okra.For more information from Lincoln University Cooperative Extension see The Harlequin Bug fact sheet.

Brown Marmorated Stink Bug

The presence of breeding populations of the invasive Brown Marmorated Stink Bug in Missouri has been found in Missouri. The Brown Marmarated Stink Bug (BMSB) is a voracious plant eater that can cause serious economic damage to fruits and vegetables, and to some agronomic and ornamental crops. Preferred fruit crops are peach, Asian pear, pear, apple, cherry, raspberry, grape, and currant. Some agronomic crops that can be damaged by this pest are soybean and corn. Among vegetables, BMSB seems to prefer green beans, asparagus, and peppers. Crabapple, persimmon, catalpa, walnut, maple, basswood, sweet gum, redbud, honeysuckle, and American holly are only some of the ornamental trees / shrubs that can be used by BMSB to feed and reproduce. These pests also get into houses. For more information see the complete article of information see the Intergrated Pest Management page

   Spotted wing drosophila (SWD)

The SWD has been spotted in Jefferson County A new invasive insect pest is threatening Missouri fruit crops. Last year the spotted wing drosophila (SWD) hit berries and other small fruit crops across the state. To find out more information before this becomes a major problem for your local fruit crop production or home garden, contact the Extension office for information about making a trap to find out if this pest is in your area.

Emerald Ash Borer   Emerald Ash Borer (EAB)

The emerald ash borer (EAB) has been found in St. Charles County, marking the destructive insect’s first known infestation in the St. Louis area. Left unchecked, EAB is fatal for all three of the state’s native ash trees—blue, green and white ash. Pumpkin ash, a popular ornamental tree, is also susceptible. While mountain ash and prickly ash have “ash” in their name, they are not true ash trees and are not at risk. For more information about this destructive insect check out the University of Missouri Extension website: You can also find out more information on this and other invasive tree pests here: 


Fire blight is caused by a bacterium, Erwinia amylovora. Rapid death of shoot tips occurs in spring. Leaves cling to a dead shoot which often has a rounded bend (or crook) at the end. Occasionally branch cankers occur. Both edible and ornamental pear varieties are susceptible although some resistance is present in certain varieties. In recent years fire blight symptoms have been observed on ornamental pear varieties formerly considered to be resistant. Severe pruning and excessive fertilization, which promote the rapid growth of succulent tissue, will also increase the vulnerability to fire blight. For more information about the correct way of pruning your trees to save them, check out this video from Nathan Brandt, UM Horticulture Specialist in St. Louis County.