The Elm Bark Beetle carries the disease and simply thrives in the hot weather. Steinbach's Elm trees are at an even greater risk of catching Dutch Elm disease this summer than years previous.  The reason is the hot, dry weather we've had.  The Elm Bark Beetle carries the disease and simply thrives in the hot weather.  Erna Wiebe, manager of Oakridge Greenhouse tells us to make matters worse most trees are suffering from draught.  She adds this is usually the time of year when leaves start to yellow and show other signs of Dutch Elm disease.