Oak galls won’t cause much permanent damage
ROLLA, Mo. –Oak trees across a broad swath of Missouri are experiencing an unusual outbreak of a common parasite. Tree experts say the parasite is not fatal to healthy trees, even though the condition can look awful. The Missouri Department of Conservation is receiving numerous reports from St. Louis to Branson of oak trees turning brown. The problem is especially severe in the area around Rolla, Lake of the Ozarks, Springfield and Table Rock Lake. The main cause of the problem is a wasp of the family Cynipidae. These tiny wasps deposit their eggs on emerging leaves in the spring. As the eggs hatch and young wasp larvae begin feeding, leaves develop brown spots that grow into “galls.” Each of these button-like growths, which are about the size of a pinhead, provides food and shelter for one wasp larva. In severe cases, entire leaves turn brown over much of a tree. “It looks worse than it really is,” said Conservation Department Resource Scientist Rob Lawrence. “Some people mistakenly t...