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Preparing Your Trees for WinterFriday, November 4th 2011 Trees can be badly damaged during severe winter storms. Trees are biologically engineered to adjust to most of the things that "Mother Nature" dishes up. Read More So You Have A Storm Damaged Tree- Now What?Tuesday, January 4th 2011 It happens far too often. You intended to get that branch that tree trimmed up, the crown reduced or have the interior of the tree pruned so it didn’t have as much volatility in a storm (so important with Bradford Pear trees) but you just never made the call to the tree care company and your you have a storm damaged tree. Read More Downed Tree Removal The List You Need To Keep HandyTuesday, January 4th 2011 The sirens have finally shut off & the winds have died down & Mother Nature has taken quite a toll on your home & yard. You go outside to assess the damage & you notice that one of your trees is down. Read More Emergency Tree Removal ServiceTuesday, January 4th 2011 A huge storm just rolled through your area leaving in its wake downed trees & power lines. Now what do you do in order to get your life back to “normal” as soon as possible? Your first call should be to emergency phone line of your power company if live lines are lying on the ground. Read More 1 2 3 4 5 6 7 Next |
FOREST HEALTH ALERT: Jumping Oak GallWednesday, March 4th 2009 By Rob LawrenceForest Entomologist Forest Health Program Missouri Department of Conservation – June 2008 Problem: Leaves on entire crowns of white oak trees turn brown in early summer. In some cases, whole hillsides appear to be browning. Individual leaves turn brown starting at the margins, and sometimes curl up and turn black. Tree Species: White oak (Quercus alba) primarily, and some other white oak group species. Description: Leaf damage is caused by high populations of a jumping oak gall wasp (Neuroterus sp.) These very tiny, stingless wasps cause pinhead-size galls to form on the undersides of leaves. Each round, button-like gall contains one wasp larva. Galls begin dropping from leaves in early summer, but brown pockmarks remain where galls had been attached. Scorch-like necrotic areas appear on leaves where many galls are present. In more severe cases, leaves turn black, curl up and drop early from trees. Gall development begins when adult female wasps deposit eggs on young expanding leaves in spring. As wasp larvae hatch out and begin feeding, trees respond with formation of a gall around each developing larva. Galls drop from leaves in early to mid-summer. Fallen galls are sometimes observed to “jump” due to vigorous movements of larvae within, much like the moth larvae of Mexican “jumping beans.” This larval behavior allows jumping oak galls to fall deeper into grass and leaf litter where they are sheltered throughout the coming winter. A new generation of adults emerges in the following spring. Jumping oak gall outbreaks typically last for one or two years and then fade away as natural controls reduce gall wasp numbers again. For example, other species of minute wasps are known to parasitize Neuroterus spp. gall wasps. Recommendations: Leaf galls rarely have a significant impact on tree health. Controls are not warranted and are not practical due to difficulty in timing treatment applications. The best tactic is using good tree care practices that reduce tree stress (mulching, watering during dry periods, avoiding root disturbances). Further Information (Internet Sources) http://ppdl.org/dd/id/jumping_oak_leaf_gall-oak.html http://waynesword.palomar.edu/pldec97.htm |
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