Re: Who would volunteer to save the hemlocks?
Posted: Wed May 14, 2014 12:41 pm
I confess to not having read all the links so I am less than optimally informed to comment. i don't want to rely on superstition, but i also recognize that not all questions and judgements can be made on a purely scientific basis. anyway, the beetle approach seems preferable. i would urge Mr. Weber, and any citizen, to call their representatives and have them direct the resources of the FS, Dept. of Agriculture, and University researchers to focus on the beetle breeding program.... sorry i can't spend more time looking into this myself, i plan on trying to contact researchers here locally...
thanks all-
Excerpted from one of TRADMIKE's links:
Relative Effectiveness
Adults and larvae of S. tsugae are highly mobile and voraciously feed on all life stages of A. tsugae. During its development, each beetle larva consumes about 500 adelgid eggs or from 50 to 100 adelgid nymphs, depending upon the size of prey attacked. Adults can live for more than one year and may consume about 50 adelgid nymphs each week during times of peak feeding activity. Each female beetle lays nearly 300 eggs in her lifetime.
Sasajiscymnus tsugae is an important predator of A. tsugae in Japan, killing 86 to 99% of the adelgids at the 24 sites were it was studied. Experiments conducted at four sites in Connecticut and one site in Virginia from 1995 through 1997 revealed that releasing relatively few adult beetles (2,400-3,600) into an infested hemlock forest reduced adelgid densities by 47-88% on release trees in only 5 months. In the field, S. tsugae mated, reproduced, and dispersed from release trees and became established in the surrounding hemlock forest. Field recoveries in Connecticut showed that S. tsugae overwintered successfully from 1996-2005 under a wide variety of climatic conditions. Adults and larvae were recovered at 65% of Connecticut release sites one to six years after the initial release. Severe winters in the northeast in 2003, 2004, and 2009 have impacted survival of hemlock woolly adelgid, keeping Connecticut forest populations of this pest patchy and low and generally non-damaging. While S. tsugae has been difficult to recover at ground level using lower crown beat sampling, bucket truck sampling has shown that adults and larvae could be found between 5-20m in the upper canopy in Connecticut and New Jersey, indicating that adults are highly mobile and disperse upwards. Environmental conditions of cool, wet summers and cold winters have aided hemlock recovery in Connecticut. Recovery in adelgid-infested stands has been recorded statewide in Connecticut since 2005, while hemlock mortality has been minimal since 2002. More recently, in 2008 and 2009, adults and larvae of S. tsugae were recovered during lower canopy beat sampling in 22% of release sites in the Great Smoky Mountains National Park. Recoveries were made in 21% of the sites sampled, with most beetles recovered from older release sites. These studies suggest that S. tsugae releases have been successful and that the beetle has excellent potential for further biological control of A. tsugae.
thanks all-
Excerpted from one of TRADMIKE's links:
Relative Effectiveness
Adults and larvae of S. tsugae are highly mobile and voraciously feed on all life stages of A. tsugae. During its development, each beetle larva consumes about 500 adelgid eggs or from 50 to 100 adelgid nymphs, depending upon the size of prey attacked. Adults can live for more than one year and may consume about 50 adelgid nymphs each week during times of peak feeding activity. Each female beetle lays nearly 300 eggs in her lifetime.
Sasajiscymnus tsugae is an important predator of A. tsugae in Japan, killing 86 to 99% of the adelgids at the 24 sites were it was studied. Experiments conducted at four sites in Connecticut and one site in Virginia from 1995 through 1997 revealed that releasing relatively few adult beetles (2,400-3,600) into an infested hemlock forest reduced adelgid densities by 47-88% on release trees in only 5 months. In the field, S. tsugae mated, reproduced, and dispersed from release trees and became established in the surrounding hemlock forest. Field recoveries in Connecticut showed that S. tsugae overwintered successfully from 1996-2005 under a wide variety of climatic conditions. Adults and larvae were recovered at 65% of Connecticut release sites one to six years after the initial release. Severe winters in the northeast in 2003, 2004, and 2009 have impacted survival of hemlock woolly adelgid, keeping Connecticut forest populations of this pest patchy and low and generally non-damaging. While S. tsugae has been difficult to recover at ground level using lower crown beat sampling, bucket truck sampling has shown that adults and larvae could be found between 5-20m in the upper canopy in Connecticut and New Jersey, indicating that adults are highly mobile and disperse upwards. Environmental conditions of cool, wet summers and cold winters have aided hemlock recovery in Connecticut. Recovery in adelgid-infested stands has been recorded statewide in Connecticut since 2005, while hemlock mortality has been minimal since 2002. More recently, in 2008 and 2009, adults and larvae of S. tsugae were recovered during lower canopy beat sampling in 22% of release sites in the Great Smoky Mountains National Park. Recoveries were made in 21% of the sites sampled, with most beetles recovered from older release sites. These studies suggest that S. tsugae releases have been successful and that the beetle has excellent potential for further biological control of A. tsugae.