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class=3DMsoNormal><o:p>&nbsp;</o:p></p></div> This is a multi-part message in MIME format. --Boundary_(ID_EulGWNYOVK3gKsxi6b3YtA) Content-type: text/plain; charset=utf-8; format=flowed Content-transfer-encoding: 8BIT It's worthwhile questioning the ability of spring migrants to spread insects, such as the hemlock woolly adelgid (HWA). Invariably it's us humans who are the direct/indirect original vectors of introduction (and this is the case with HWA as well). I am interested to learn more about the spring migration routes of species such as Bay-breasted and Blackburnian warblers, as well as Blue headed vireo, and other high canopy gleaners of insects in hemlock stands. I understand that HWA has been migrating more or less steadily toward northern Maine over the past decades, slowed somewhat by some of the colder winters. Everything points to it reaching there eventually. Since the pest consists of "all females", HWA needs only one new individual to start a whole new population. (We can only hope this could lead to part of its vulnerability.) HWA needs to actually land on hemlock. I am not certain that NB has a lot of hemlock at the border, but it likely features much less than it once did, given the species sensitivity to fire, land clearance and clearcuts. (My research in eastern NB indicated a precipitous decline in expansive hemlock-dominated stands beginning in the early 1800s.) There may be much less hemlock to become infested with HWA in NB than in southwestern NS where some impressive hemlock stands remain. Other plausible theories for HWA dispersal vectors to NS were from high wind events and nursery stock. Birds seemed more likely to me, especially given the extremely small size of HWA and its ability to stick fast to feathers. It's heart wrenching to watch. Donna Crossland On 2018-06-15 8:07 AM, John Kearney wrote: > > Hi David and all, > > That’s a very good question. I’ve heard the same reason given for why > we have the Hemlock Woolley Adelgid in Nova Scotia but not in northern > Maine and New Brunswick. I’m not aware of any evidence indicating that > more spring migrants fly to Nova Scotia than Maine or New Brunswick. > > John > > *From:*naturens-owner@chebucto.ns.ca <naturens-owner@chebucto.ns.ca> > *On Behalf Of *David > *Sent:* Thursday, June 14, 2018 17:10 > *To:* naturens@chebucto.ns.ca > *Subject:* [NatureNS] Lyme disease > > Dear All, > > In the July issue of Maclean's (p.17) are interesting data on Lyme > disease incidence in Canada. The much higher incidence in NS, 21.5 > times as high as the average incidence in the other nine provinces, is > attributed to "climate and the large number of migratory birds > carrying ticks from the US." > > I don't follow why NS would be hit the hardest. > > Yt, DW > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus --Boundary_(ID_EulGWNYOVK3gKsxi6b3YtA) Content-type: text/html; charset=utf-8 Content-transfer-encoding: 8BIT <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <p>It's worthwhile questioning the ability of spring migrants to spread insects, such as the hemlock woolly adelgid (HWA). Invariably it's us humans who are the direct/indirect original vectors of introduction (and this is the case with HWA as well). I am interested to learn more about the spring migration routes of species such as Bay-breasted and Blackburnian warblers, as well as Blue headed vireo, and other high canopy gleaners of insects in hemlock stands. <br> </p> <p>I understand that HWA has been migrating more or less steadily toward northern Maine over the past decades, slowed somewhat by some of the colder winters. Everything points to it reaching there eventually. Since the pest consists of "all females", HWA needs only one new individual to start a whole new population. (We can only hope this could lead to part of its vulnerability.) <br> </p> <p>HWA needs to actually land on hemlock. I am not certain that NB has a lot of hemlock at the border, but it likely features much less than it once did, given the species sensitivity to fire, land clearance and clearcuts. (My research in eastern NB indicated a precipitous decline in expansive hemlock-dominated stands beginning in the early 1800s.) There may be much less hemlock to become infested with HWA in NB than in southwestern NS where some impressive hemlock stands remain. Other plausible theories for HWA dispersal vectors to NS were from high wind events and nursery stock. Birds seemed more likely to me, especially given the extremely small size of HWA and its ability to stick fast to feathers.</p> <p>It's heart wrenching to watch.<br> </p> <p>Donna Crossland<br> </p> <br> <div class="moz-cite-prefix">On 2018-06-15 8:07 AM, John Kearney wrote:<br> </div> <blockquote type="cite" cite="mid:000001d40499$12fc0280$38f40780$@ns.sympatico.ca"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style><!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} @font-face {font-family:"Segoe UI"; panose-1:2 11 5 2 4 2 4 2 2 3;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0cm; margin-bottom:.0001pt; font-size:11.0pt; font-family:"Calibri",sans-serif;} a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {mso-style-priority:99; color:purple; text-decoration:underline;} p.msonormal0, li.msonormal0, div.msonormal0 {mso-style-name:msonormal; mso-margin-top-alt:auto; margin-right:0cm; mso-margin-bottom-alt:auto; margin-left:0cm; font-size:11.0pt; font-family:"Calibri",sans-serif;} span.EmailStyle18 {mso-style-type:personal-reply; font-family:"Calibri",sans-serif; color:windowtext;} .MsoChpDefault {mso-style-type:export-only; font-size:10.0pt;} @page WordSection1 {size:612.0pt 792.0pt; margin:72.0pt 72.0pt 72.0pt 72.0pt;} div.WordSection1 {page:WordSection1;} --></style><!--[if gte mso 9]><xml> <o:shapedefaults v:ext="edit" spidmax="1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v: