Impacts of pear thrips on a Pennsylvania sugarbush: third year results

Abstract

Pear thrips, Taeniothrips inconsequens (Uzel) (Thysanoptera: Thripidae), were first positively identified as causing damage to sugar maple (Acer saccharum Marsh.) in forest environments in the United States in 1980. Damage in Pennsylvania from this insect has occurred consistently since 1980, with the most extensive impact in 1988 (0.5 millon ha). Sap characteristics and crown condition were monitored for three years following a 1989 thrips attack in a Pennsylvania sugarbush on 56 trees representing a range of thrips damage. Heavy damage in 1989 was associated with increased crown transparency for two summers following the attack. Calculated syrup production was greatest in all years for trees with light damage and lowest for trees with heavy damage. Reduced syrup production in trees with heavy damage resulted from lower sap volume in all years and lower sap sugar concentration in 1990 and 1992 compared to trees with light damage. The results indicate that pear thrips damage in 1989 had a detrimental impact on sugar maple health and syrup production for three years following the attack.

Citation

Kolb, Thomas E.; McCormick, Larry H. 1993. Impacts of pear thrips on a Pennsylvania sugarbush: third year results. In: Gillespie, Andrew R.; Parker, George R.; Pope, Phillip E.; Rink, George: eds. Proceedings of the 9th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-161. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 119-129