Q. This year we had a tremendous plague of wasps in the suka, is it permitted to put a screen on top of the schach since it lets trough rain and light?
A. Horav Shlomo Miller's Shlit' opinion is that technically it would be possible to create a screen that would be permitted when intermingled with the schach. However in practice, existing commercial screen material may not comply with the Halacha requirements.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a.