Infested Tree (IMAGE) Penn State Caption This is Ailanthus bolt with the bark removed showing the Fusarium fungus farmed by the abrosia beetle growing out from the galleries. Credit Matthew Kasson, Penn State Usage Restrictions non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.