[NatureNS] How is the wild food supply?

Date: Wed, 11 Nov 2009 17:45:38 -0400
From: Eleanor Lindsay <kelindsay@eastlink.ca>
To: NatureNS <NatureNS@chebucto.ns.ca>
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instance in the genus &lt;i&gt;Ips&lt;/i&gt;, that are s
Thanks Chris!

Eleanor

Christopher Majka wrote:
> Hi Eleanor,
>
> On 11-Nov-09, at 9:07 AM, Eleanor Lindsay wrote:
>
>> I think there are some very distinct regional differences in this 
>> year's wild food supply. The spruce bark beetle, which I understand 
>> is native to Nova Scotia and normally kept in check by cold 
>> winters...) has created quite severe and rapid devastation in some 
>> parts of the province, in particular the east side of St Margarets 
>> Bay, (especially Seabright and Glen Margaret), where whole chunks of 
>> spruce forest have died off in the space of the last 2-3 years and 
>> also, I believe in parts of Antigonish County and Cape Breton. So 
>> cones for squirrels, for example, must be severely reduced or non 
>> existent in these areas.
>
> In North America the name "spruce bark beetle" is normally applied to 
> Dendroctonus rufipennis, although in Europe, the name indicates 
> another species, Ips typographicus. Dendroctonus rufipennis is a 
> native species in Nova Scotia, indeed it occurs throughout North 
> America from Alaska to Newfoundland and south into the USA wherever 
> spruce grow. Although most of the recent attention on the relationship 
> of climate change to bark beetle infestations has been devoted to the 
> mountain pine beetle (Dendroctonus ponderosae), there are considerable 
> similarities between the two species. There are two climate related 
> effects:
>
> 1) Prolonged cold temperatures during the winter can kill some of the 
> overwintering beetles. As we experience climate change, and prolonged 
> cold snaps in winter become less frequent, this bioregulation 
> mechanism becomes less effective. For example, studies in the southern 
> United States on the similar southern pine beetle (Dendroctonus 
> frontalis) have linked outbreaks there to a warming trend from 1960 to 
> 2004 of 3.3°C in minimum winter air temperatures.
>
> 2) Spruce bark beetles normally complete their life cycles in either 
> one or two years (rarely three, in cold northern regions). As climate 
> changes and temperatures warm, a greater proportion of beetles can 
> complete their life cycles in a shorter period of time, leading to 
> faster turnover and greater utilization of resources (i.e., they chew 
> through spruce more quickly ;->).
>
> In other bark beetles, for instance in the genus Ips, that are 
> sometimes univoltine (i.e., one generation per year), or bivoltine 
> (two generations per year), warming temperatures mean that a greater 
> proportion of the population becomes bivoltine, again with the same 
> consequences: population levels increase and they consume more food 
> (most bark beetles are cambium feeders, feeding on the inner bark of 
> trees).
>
> The USDA Forest Service has a good web page on Dendroctonus rufipennis:
>
> http://www.na.fs.fed.us/spfo/pubs/fidls/sprucebeetle/sprucebeetle.htm
>
> Cheers!
>
> Chris
>
>
> Christopher Majka  <c.majka@ns.sympatico.ca> | Halifax, Nova Scotia, 
> Canada
>
> * Research Associate: Nova Scotia Museum | 
> http://museum.gov.ns.ca/mnh/research-asfr.htm
> * Review Editor: The Coleopterists Bulletin | http://www.coleopsoc.org/
> * Subject Editor: ZooKeys | 
> http://pensoftonline.net/zookeys/index.php/journal/index
> * Associate Editor: Journal of the Acadian Entomological Society | 
> http://www.acadianes.org/journal.html
> * Editor: Atlantic Canada Coleoptera | 
> http://www.chebucto.ns.ca/Environment/NHR/atlantic_coleoptera.html
>
> "Whenever I hear of the capture of rare beetles, I feel like an old 
> war-horse at the sound of a trumpet." - Charles Darwin
>
>
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