hello. Is dormant oil effective if applied around July1? As for the crawlers, when will they emerge, and with what do you recommend spraying them? How can you know they have emerged? The tree is tall and the crawlers are tiny!
Extension
Message
From:
Richard Hentschel
Extension Educator, Horticulture
DuPage/Kane/Kendall Unit hentsche@illinois.edu
Dormant oils are normally done while the plant does not contain foliage in late winter to early spring and controls overwintering scales. A more complete story can be found at: http://hyg.ipm.illinois.edu/article.php?id=729
Crawlers emerge and move to younger twigs and foliage. there feeding usually means that you will see tiny droplets of sap on car finishes and furniture. The sap can also support sooty mold easily seen
