[DOWNLOAD] "Invasion of the Hemlock Woolly Adelgid on Eastern Hemlock in the Great Smoky Mountains National Park." by Journal of the Tennessee Academy of Science " Book PDF Kindle ePub Free

eBook details

Title: Invasion of the Hemlock Woolly Adelgid on Eastern Hemlock in the Great Smoky Mountains National Park.
Author : Journal of the Tennessee Academy of Science
Release Date : January 01, 2006
Genre: Engineering,Books,Professional & Technical,
Pages : * pages
Size : 206 KB

Description

ABSTRACT -- Light to moderately-heavy hemlock woolly adelgid infestations on eastern hemlocks were discovered in the Great Smoky Mountains National Park in 2002. Mass releases of the biological control agent, Sasajiscymnus tsugae, were made initially at ten sites infested with the hemlock woolly adelgid. These sites were monitored through 2003 to assess the establishment of S. tsugae, the density of the adelgid population, and the impact on the health of eastern hemlocks. The average number of hemlock woolly adelgids at the study sites evaluated was 242 (85-412) on the terminal 25 cm of branches. The highest average number of hemlock woolly adelgids (412) from 10 samples per release tree occurred at the Laurel Falls 1 site and the lowest number (85) at the Gregory Ridge site. The average hemlock woolly adelgids per sample for infested trees 10 to 28 m from the release tree averaged 126 (0-478). Initial data indicate that tree transparency was negatively correlated to the increase in hemlock woolly adelgid population numbers. None of the sites sampled had average crown transparencies less than 50%. These data indicate this invasive pest was not established long enough at the time of this study to impact the overall health of sampled trees, but has since become well established. Released lady beetles were recovered at three sites in the fall of 2002. With the rapid spread of the hemlock woolly adelgid throughout the area, additional releases of the lady beetles were made to reduce populations of this invasive pest. **********