UNIVERSITY PARK, Pa. — The Penn State Office of Physical Plant (OPP) will conduct tree spraying May 11-12 at the University Park campus to combat Dutch elm disease and elm yellows, as well as mitigate spongy moth infestations.

Aerial application by helicopter will begin at first light on Thursday, May 11, in the areas of east campus, Hort Woods, the Penn State Golf Courses, and outlying oak stands. Ground spraying will commence at 9 p.m. on Thursday, May 11, and continue until 3 a.m. Friday, May 12. A final aerial spray of the campus’ historic elm trees will take place at daybreak on Friday, May 12.

Both aerial and ground-based applications are weather-permitting. Signage will be posted in the affected areas, and ground support crews will be present.

OPP sprays the elm trees each year in May and July to slow the spread of both Dutch elm disease and elm yellows, and to protect the remaining iconic elms on the University Park campus. These applications are carefully timed to best control the pest and benefit the trees, and to be as minimally invasive as possible to the campus community, including people and wildlife.

This year, Penn State also will be spraying to combat potential spongy moth infestations. The spongy moth is a non-native forest pest that can defoliate large stands of deciduous trees. The timing of this campus spray coincides with similar local municipality efforts and is meant to minimize the effect on desirable pollinator species.

OPP thanks the campus community for understanding the need and cooperating with this important program aimed at preserving the campus’ trees.