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The Global Invasive Species Team | |
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Global Invasive Species Team listserve digest #051 Tue, 11 Jan 2000 14:32:21 -0800 (PST) --CONTENTS-- 1. Polygonum cuspidatum spreading by fragments (Tennessee) 2. Barkless pines (Kentucky) --------------------------------------- 1. Polygonum cuspidatum spreading by fragments (Tennessee) From: Kris Johnson (Kris_Johnson(at)nps.gov) Regarding the spread of Japanese knotweed in riparian areas: At Great Smoky Mountains National Park, we have found that knotweed spreads readily from infested tributary stream areas outside the park into the main channel where we must constantly search for and destroy new infestations. These mountain streams flood frequently in spring and I suspect that plant fragments are uprooted and deposited in the scoured riparian zone, where they are able to root. And/or the seeds may be washed down and germinate. --------------------------------------- 2. Barkless pines (Kentucky) From: Augusta Mazyck (kmazyck(at)tnc.org) Since the TNC weed listserve has been expanded to include insects, I thought this might be relevant. I was recently on a preserve in Eastern Kentucky, at a relatively high elevation for the area (this creates a pretty unique area--many species found here are generally found in much cooler regions) and saw a number of pitch pines that had been stripped completely of their bark. I have never heard of anything like this before, and was wondering if anyone had any ideas. Insects or rodents maybe? Someone suggested porcupines, though they have never been reported in the area. Any ideas would be much appreciated. --Most insects that damage trees tend to be borers (beetles that tunnel into the wood) that leave small holes and tunnels underneath the bark. However, the twig girdler is a long horned beetle that often feeds on tender bark and tips of twigs as adults. Branches can be girdled and often fall to the ground. Weevils (pales and pitch-eating) do chew bark but generally from small seedlings. In Australia, young trees are fed upon by caterpillars (the native budworm Helicoverpa punctigera) and eat foliage and strip bark. --TunyaLee Morisawa, Exotic Species Team |
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