URI_Research_Magazine_Momentum_Spring_2016_Melissa-McCarthy

eastern hemlock was unable to inter-breed. Lastly, the U.S. Forest Service attempted biological controls — wherein a different species is introduced to prey on adelgids. Up until now, there has been little success using this method, but Preisser says it may hold potential for the future. However, there exists a different method that Preisser has worked on

role in combating invasive species. Among the series of generalized approaches pursued, one involves developing an effective chemical control for that particular organism. In the case of adelgid, there are some very good chemical controls available. In particular, neonicotinoid pesticides have proved effective against adelgids, but they come with some problems. “They can’t be used near water, and although they aren’t particularly toxic to mammals or birds, they’re quite broad-spectrum for invertebrates,” Preisser explains. “They have a big effect on pollinators.” This means that widespread use of neonicotinoids is not possible — so the U.S. Forest Service turned to other methods, including inter-specific hybridization, which would cross eastern and Carolina hemlock with Asian hemlock, a species that coexist with adelgids. That had some

extensively that may offer another means of combating this pest. After surveying hemlock forests, he began to wonder if, in areas ravaged by adelgids, he could find a few trees that survived the onslaught. Such trees would likely possess some sort of rare innate resistance to the insects. Preisser developed a citizens’ science program that searched for these lone survivors.

The program turned up a number of candidate trees,

moderate success with Carolina hemlock, but

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{ momentum: Research & Innovation }