Scots Pine, D. Zimmermani Control, Illinois, 1977

Abstract

Abstract A 5-acre nursery of Scots pine trees of 4-6 ft in height planted 4 feet apart and consisting of 14 rows with ca 100 trees per row was selected in Whiteside County, Illinois because of the high incidence of Zimmerman pine moth damage. On September 10, 1976, 9 trees that had symptoms of Zimmerman pine moth infestations were tagged in each of 14 rows. On September 14, 1976, insecticide sprays were applied until runoff onto the branches and trunks of the trees, using a 100 gallon hydraulic sprayer. Each treatment was applied onto 9 trees in each of 2 adjoining rows. On April 16, 1977 other trees in adjoining rows were treated as described in the September 14 applications, using the same insecticides. On May 20, 1977 the hardened sap exudate from previous infestations was scraped off all the tagged trees. On August 12, 1977 the number of new infestation sites seen as sap exudate was counted on each tree.