No. 13/October 9, 2019

Brown Marmorated Stink Bug
Brown marmorated stink bug (Halyomorpha halys; BMSB) is an introduced species from Asia that was first recorded in Illinois in 2010.  BMSB can feed on over 300 species of plants.  It can be a pest of fruits, vegetables, field crops and ornamental plants.  In ornamental plants, this can include maples, oak, spirea, viburnum, rose and ornamental fruit trees, among many others.  These insects have straw-like mouthparts that they use to suck fluids from plants.  The resulting injury can look like discoloration or dead patches on leaves.  In fruits and vegetables, injury can appear as discoloration, lesions or cat-facing.

Prepare for Chickweed Germination
Temperatures are finally cooling off and our cool season annual weeds are really starting to germinate. If you have not applied already, now is the time to get a preemergent herbicide down. Mulch also works well to prevent germination in landscape beds.

Biscogniauxia Canker and Dieback
Biscogniauxia (pronounced Bisk-o-nee-ox-e-a) canker and dieback is a disease that takes advantage of stressed and weakened host trees.  Outbreaks of the disease occur following stress events.  These events may include growing seasons with intense heat, prolonged drought, or any injury to a tree’s root system. While the disease is capable of infecting a variety of tree species, oaks within the red oak group are particularly susceptible. Over the past several years, I have observed numerous pin oaks in central Illinois succumb to this disease.

Apple Scab Prevention for 2020
Has apple scab been a problem on your crabapples this year? At this point in the season, many apples and crabapples have lost most of their leaves and appear quite bare are a result of this disease. Apple Scab is an extremely common fungal disease of apple and crabapple caused by the pathogen Venturia inaequalis. Symptoms first appear as olive-green spots on the foliage.  The spots often form along or near the leaf veins, eventually developing a dark, velvety appearance. Infected leaves also may appear curled or puckered.  By mid-summer, infected leaves turn yellow, and prematurely drop from the tree.  Apple scab will not kill a tree, but it has the ability to make a tree appear rather unsightly. Additionally, repeated defoliation may weaken a tree resulting in reducing growth, flowering, and increased susceptibility to other stresses.  Fortunately, you have a variety of options to help reduce damage from apple scab for the 2020 growing season.