One of the biggest insects in Wisconsin is the scarab beetle, Osmoderma. Large C-shaped grubs can be found in rotting stumps and the adults appear in July and August. Adults are up to 3 cm long and are strongly attracted to lights at night. They are harmless and remind many of the large beetles found in the tropics. There is sometimes a strong odor of leather when captured and which leads to the name “leather beetle.” They are also called the Hermit Flower beetle.