The Penn State Forestland Management Office is currently developing a strategy to manage the impact attributed to the non native Hemlock Woolly Adelgid within the boundaries of the Stone Valley Forest and the Weaver Forest. Visit the DCNR BOF Hemlock Woolly Adelgid website for information pertaining to the insect's description, life cycle, distribution and control.

The USDA has reported infestations of Woolly Adelgid in both Huntingdon and Centre counties since 2001. PSU Forestland Management Office personnel have observed small populations of Woolly Adelgid in the Shaver Creek Valley of the Stone Valley Forest (Huntingdon County) since the summer of 2003. Increased observations of infestations and randomly dead hemlocks during the late fall/early winter of 2004 prompted the Forestland Management staff to attempt to regenerate an infested hemlock stand using a silvicultural treatment. Infested, intermediate and suppressed hemlock trees were mechanically removed within a 12 acre stand and processed for pulpwood. All mature hardwood and healthy dominate hemlock trees were retained to control the temperature and sunlight in the stand. The hope is the stand's seedbed will naturally regenerate the stand with a diverse mixture of maples, black cherry, yellow poplar, ash and white oak (fall 2004 was a mast year for white oak in the Stone Valley Forest). Permanent inventory and photo plots were established throughout the stand to monitor the stand's response.

The PSU Forestland Management Office has increased its surveying and monitoring for Woolly Adelgid. Transect counts to assess infestations have been conducted within the Lower and Upper Shaver Creek Valleys of the Stone Valley Forest. Preliminary findings indicate a more wide spread infestation in the Upper Valley. A Weaver Forest assessment yielded no occurrences of Hemlock Adelgid.