No. 16/October 6, 2014

Seasonal Needle Drop
Around this time of year, the U of I Plant Clinic receives many calls regarding yellowing needles on evergreens. The appearance can be quite alarming to homeowners whose seemingly healthy evergreens suddenly turn yellow and drop large numbers of needles. Fortunately, most are witnessing a harmless and natural part of the plant's cycle.

Powdery Mildews
Powdery mildew is caused by a large number of related fungal pathogens. It is common on a wide variety of hosts, including ornamental plants (examples: peony, phlox, rose, zinnia, lilac), vegetables (examples: beans, cucurbits such as cucumber, pumpkin, and squash), woody trees and shrubs (examples: oak, crabapple, rhododendron), and turf grass. Each species of the pathogen affects a smaller subset of hosts.

Red Oak Borer
Red oak borer, Enaphalodes rufulus, is a longhorned beetle that attacks live oak trees, causing primarily cosmetic damage to landscape oaks in the form of oval exit holes about one-half inch long in the trunk and piles of wood fibers and frass at the base of the tree.

Planting for Pollinators
The reductions in honey bees and other pollinators in recent years have been making headlines in the mass media. There are a number of factors associated with these declines including loss of habitat, parasites, disease, genetics, poor nutrition, and pesticide exposure. Perhaps the biggest factor is loss of habitat.

Emerald Ash Borer
The Emerald Ash Borer (EAB) has been confirmed in 14 new counties, including five that are located outside the current state quarantine zone intended to prevent the spread of the beetle.