No. 15/August 27, 2010
Whiteflies are being found commonly in the landscape, feeding on the leaves of flowers and other herbaceous plants as well as hydrangea, other shrubs, and trees. Generally, late season whiteflies can be ignored, as they are too late to cause serious damage to plant health or even cause obvious aesthetic damage.
White Pine Sawfly
White pine sawfly larvae have been reported from Henry County in northwestern Illinois and Champaign County in east central Illinois feeding on white pine. White pine sawfly, Neodiprion pinetum, feeds on both the younger and older needles of white pine, mugo, and red pines, resulting in branches completely stripped of foliage.
Redheaded Pine Sawfly
Redheaded pine sawfly feeds primarily on two- and three-needle pines, being particularly common on Scotch, jack, and red pines. It also feeds on five-needle pines, Norway spruce, and larch growing near two- or three-needle pines. It tends to prefer weakened trees, those growing in poor sites, stressed by drought, or growing in competition with other plants.
White grubs in moderately damaging numbers have been reported in east central Illinois. Be vigilant for wilting and browning turf areas.
University of Illinois Plant Clinic Seasonal Closing Notice
It is almost time for the Plant Clinic to close its doors for the season. Wednesday, September 15th, is the last day of operation for this year.