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RE: [CalOdes] Black Spreadwing ID Help

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  • Steve Rottenborn
    Inspired by Ray s photo and Dennis s comments, I visited Rosendin Pond near Morgan Hill (Santa Clara County) this afternoon, as I had photographed some
    Message 1 of 7 , May 8 10:01 PM
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      Inspired by Ray's photo and Dennis's comments, I visited Rosendin Pond near Morgan Hill (Santa Clara County) this afternoon, as I had photographed some greenish Black Spreadwings here last May.  Today I found 400+ spreadwings, including many tenerals around the pond and somewhat more mature individuals throughout the grass and scrub surrounding the pond.  Numerous immature males were extensively green on the dorsal surface of the abdomen, and many of these showed varying degrees of greenish iridescence on the  thorax as well.  However, only 1-2% were noticeably bright green on the thorax, similar to the one Ray photographed.  I posted five photos of two such individuals in the folder "Santa Clara Co. Black Spreadwings" on the CalOdes site.  The brightness of the green on the thorax varied considerably depending on the angle at which I viewed these individuals; much of the time they appeared bright green, but bronzy tones appeared at certain angles.  Around 2-3% of males I saw were mature enough to show pruinosity on the proximal and distal abdominal segments; these showed no green tones on the thorax, but they showed some greenish iridescence on the abdomen.

      Taxonomic uncertainty regarding the relationship of Emerald and Black Spreadwing notwithstanding, the variability present at Rosendin Pond must represent variability in what we currently consider to be Black Spreadwings, based on both range and on the fact that I've never seen a mature male Emerald Spreadwing (which should be conspicuous) at this location.  My photos are not as good as Ray's, but those few bright individuals looked every bit as green as the one Ray photographed (this is best shown on the photo "Black Spreadwing1a").

      I focused on spreadwings so did not note everything else at the pond, but I did see my first Red-veined Meadowhawk of the year, in addition to Cardinal and Variegated Meadowhawks.

      Steve Rottenborn
      Morgan Hill, CA

       

       

      From: CalOdes@yahoogroups.com [mailto:CalOdes@yahoogroups.com] On Behalf Of Dennis Paulson
      Sent: Saturday, May 08, 2010 7:49 AM
      To: Ray Bruun
      Cc: Cal Odes
      Subject: Re: [CalOdes] Black Spreadwing ID Help

       

       

      Ray,

       

      Jim Johnson pointed out a couple of years ago that populations of Emerald and/or Black Spreadwings in southwestern Oregon seem to mix green and black (we badly need a cumulative index to ARGIA, so these articles are easier to find, but this one is in the second issue of Volume 18, 2006), and several odonatologists have commented that the two are probably no more than subspecies of the same species. There was no difference found in an analysis of mitochondrial DNA in North American Lestes. No one has made the "official" recommendation to change their status, however, so for now they are still considered separate.

       

      As far as I know, the male in your photo is greener than anyone has reported for lowland California Lestes stultus, and I would call it Lestes dryas without hesitation. Jim found both types together in Oregon, with everything in between, and postmortem color change from one type t o the other sometimes occurs. Geographic variation in odonate species is still poorly documented, but this may be an example. It would be nice to have an official proposal, backed up by data, to combine these two species.

       

      Dennis

       

      On May 7, 2010, at 7:17 PM, Ray Bruun wrote:



       

      I was out photographing with Rob Santry today. We had many Black
      Spreadwing at Volonte Park in Anderson, Shasta County. At least I
      thought they were Black Spreadwing. Most are young or teneral with a
      bronze look. See this photo of a young female taken last weekend at the
      same spot - http://www.flickr.com/photos/bruunphoto/4572841048/sizes/l/

      But I photographed a spreadwing today, a young male, that is green, like
      Emerald Spreadwing. I've never seen Emerald Spreadwing in the
      Sacramento Valley proper, only in the mountains. Nor have I seen Black
      and Emerald together. The green male can be seen here -
      http://www.flickr.com/photos/bruunphoto/4587560449/sizes/o/

      Any thoughts as to ID of these two spreadwings?

      Ray Bruun
      Shingletown, Shasta County, CA

       

      -----

      Dennis Paulson

      1724 NE 98 St.

      Seattle, WA 98115

      206-528-1382

       



       

    • Dennis Paulson
      Thanks for that info, Steve. That would seem to indicate that Black Spreadwings can be green, perhaps anywhere in the range of the taxon, and the presence of
      Message 2 of 7 , May 9 7:00 AM
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        Thanks for that info, Steve.

        That would seem to indicate that Black Spreadwings can be green, perhaps anywhere in the range of the taxon, and the presence of those green individuals shouldn't influence our decision about the specific status of Black vs. Emerald. That's a step forward, in my opinion. Jim Johnson's findings were in an area in southwestern Oregon where you might expect the two to meet, so the intermediacy of populations there, if those really are intermediate populations (not just variation in either of the species), wouid be more relevant.

        A number of other usually brown/bronze metallic spreadwings can look quite green, especially on the abdomen (e.g., Lyre-tipped). Whatever structural aspect of the cuticle is giving them that shiny look, it may be very similar in the green mode and the bronze mode. We still need that study, and I would guess late May/June would be a good time for a spreadwing transect from the Sierras to the Central Valley and from central Oregon south to northern California. How about a moving Blitz, or a concerted county-by-county effort by a bunch of people? The fun thing about any such survey is that you always make additional discoveries.

        Dennis Paulson
        Seattle, WA

        On May 8, 2010, at 10:01 PM, Steve Rottenborn wrote:

        Inspired by Ray's photo and Dennis's comments, I visited Rosendin Pond near Morgan Hill (Santa Clara County) this afternoon, as I had photographed some greenish Black Spreadwings here last May.  Today I found 400+ spreadwings, including many tenerals around the pond and somewhat more mature individuals throughout the grass and scrub surrounding the pond.  Numerous immature males were extensively green on the dorsal surface of the abdomen, and many of these showed varying degrees of greenish iridescence on the  thorax as well.  However, only 1-2% were noticeably bright green on the thorax, similar to the one Ray photographed.  I posted five photos of two such individuals in the folder "Santa Clara Co. Black Spreadwings" on the CalOdes site.  The brightness of the green on the thorax varied considerably depending on the angle at which I viewed these individuals; much of the time they appeared bright green, but bronzy tones appeared at certain angles.  Around 2-3% of males I saw were mature enough to show pruinosity on the proximal and distal abdominal segments; these showed no green tones on the thorax, but they showed some greenish iridescence on the abdomen.

        Taxonomic uncertainty regarding the relationship of Emerald and Black Spreadwing notwithstanding, the variability present at Rosendin Pond must represent variability in what we currently consider to be Black Spreadwings, based on both range and on the fact that I've never seen a mature male Emerald Spreadwing (which should be conspicuous) at this location.  My photos are not as good as Ray's, but those few bright individuals looked every bit as green as the one Ray photographed (this is best shown on the photo "Black Spreadwing1a").

        I focused on spreadwings so did not note everything else at the pond, but I did see my first Red-veined Meadowhawk of the year, in addition to Cardinal and Variegated Meadowhawks.

        Steve Rottenborn
        Morgan Hill, CA
         
         
        From: CalOdes@yahoogroups.com [mailto:CalOdes@yahoogroups.com] On Behalf Of Dennis Paulson
        Sent: Saturday, May 08, 2010 7:49 AM
        To: Ray Bruun
        Cc: Cal Odes
        Subject: Re: [CalOdes] Black Spreadwing ID Help

        Ray, 

        Jim Johnson pointed out a couple of years ago that populations of Emerald and/or Black Spreadwings in southwestern Oregon seem to mix green and black (we badly need a cumulative index to ARGIA, so these articles are easier to find, but this one is in the second issue of Volume 18, 2006), and several odonatologists have commented that the two are probably no more than subspecies of the same species. There was no difference found in an analysis of mitochondrial DNA in North American Lestes. No one has made the "official" recommendation to change their status, however, so for now they are still considered separate.
         
        As far as I know, the male in your photo is greener than anyone has reported for lowland California Lestes stultus, and I would call it Lestes dryas without hesitation. Jim found both types together in Oregon, with everything in between, and postmortem color change from one type t o the other sometimes occurs. Geographic variation in odonate species is still poorly documented, but this may be an example. It would be nice to have an official proposal, backed up by data, to combine these two species.
         
        Dennis
         
        On May 7, 2010, at 7:17 PM, Ray Bruun wrote:

        I was out photographing with Rob Santry today. We had many Black 
        Spreadwing at Volonte Park in Anderson, Shasta County. At least I 
        thought they were Black Spreadwing. Most are young or teneral with a 
        bronze look. See this photo of a young female taken last weekend at the 
        same spot - http://www.flickr.com/photos/bruunphoto/4572841048/sizes/l/

        But I photographed a spreadwing today, a young male, that is green, like 
        Emerald Spreadwing. I've never seen Emerald Spreadwing in the 
        Sacramento Valley proper, only in the mountains. Nor have I seen Black 
        and Emerald together. The green male can be seen here - 
        http://www.flickr.com/photos/bruunphoto/4587560449/sizes/o/

        Any thoughts as to ID of these two spreadwings?

        Ray Bruun
        Shingletown, Shasta County, CA

      • Ray Bruun
        Nice description, Steve. I ll be keeping a lookout of the intergrades you mentioned as well as other full Emeralds, especially adults, since these may be
        Message 3 of 7 , May 9 8:08 AM
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          Nice description, Steve.  I'll be keeping a lookout of the intergrades you mentioned as well as other full "Emeralds," especially adults, since these may be rare or absent.

          Black Spreadwing isn't all that common up our way.  This is only the third location in Shasta County where I've found them, and it is by far the largest population.  Also, in our area there isn't much habitat (accessible, at least) between the valley floor (~500') and the mountain lakes where the Emerald Spreadwings reside (4,000' and up?).  Therefore, a meaningful transect may not be possible.  But I will look over Google Earth, Google Maps (I use this as a tool to find small lakes and ponds, which show up very well against the flat green [national forest] or white background color), and electronic USGS topo maps for possible locations.


          Ray Bruun
          Shingletown, Shasta County, CA



          On 5/9/2010 7:00 AM, Dennis Paulson wrote:
          Thanks for that info, Steve.

          That would seem to indicate that Black Spreadwings can be green, perhaps anywhere in the range of the taxon, and the presence of those green individuals shouldn't influence our decision about the specific status of Black vs. Emerald. That's a step forward, in my opinion. Jim Johnson's findings were in an area in southwestern Oregon where you might expect the two to meet, so the intermediacy of populations there, if those really are intermediate populations (not just variation in either of the species), wouid be more relevant.

          A number of other usually brown/bronze metallic spreadwings can look quite green, especially on the abdomen (e.g., Lyre-tipped). Whatever structural aspect of the cuticle is giving them that shiny look, it may be very similar in the green mode and the bronze mode. We still need that study, and I would guess late May/June would be a good time for a spreadwing transect from the Sierra s to the Central Valley and from central Oregon south to northern California. How about a moving Blitz, or a concerted county-by-county effort by a bunch of people? The fun thing about any such survey is that you always make additional discoveries.

          Dennis Paulson
          Seattle, WA

          On May 8, 2010, at 10:01 PM, Steve Rottenborn wrote:

          Inspired by Ray's photo and Dennis's comments, I visited Rosendin Pond near Morgan Hill (Santa Clara County) this afternoon, as I had photographed some greenish Black Spreadwings here last May.  Today I found 400+ spreadwings, including many tenerals around the pond and somewhat more mature individuals throughout the grass and scrub surrounding the pond.  Numerous immature males were extensively green on the dorsal surface of the abdomen, and many of these showed varying degrees of greenish iridescence on the  thorax as well.  However, only 1-2% were noticeably bright green on the thorax, similar to the one Ray photographed.  I posted five photos of two such individuals in the folder "Santa Clara Co. Black Spreadwings" on the CalOdes site.  The brightness of the green on the thorax varied considerably depending on the angle at which I viewed these individuals; much of the time they appeared bright green, but bronzy tones appeared at certain angles.  Around 2-3% of males I saw were mature enough to show pruinosity on the proximal and distal abdominal segments; these showed no green tones on the thorax, but they showed some greenish iridescence on the abdomen.

          Taxonomic uncertainty regarding the relationship of Emerald and Black Spreadwing notwithstanding, the variability present at Rosendin Pond must represent variability in what we currently consider to be Black Spreadwings, based on both range and on the fact that I've never seen a mature male Emerald Spreadwing (which should be conspicuous) at this location.  My photos are not as good as Ray's, but those few bright individuals looked every bit as green a s the one Ray photographed (this is best shown on the photo "Black Spreadwing1a").

          I focused on spreadwings so did not note everything else at the pond, but I did see my first Red-veined Meadowhawk of the year, in addition to Cardinal and Variegated Meadowhawks.

          Steve Rottenborn
          Morgan Hill, CA
           
           
          From: CalOdes@yahoogroups.com [mailto:CalOdes@yahoogroups.com] On Behalf Of Dennis Paulson
          Sent: Saturday, May 08, 2010 7:49 AM
          To:  Ray Bruun
          Cc: Cal Odes
          Subject: Re: [CalOdes] Black Spreadwing ID Help

          Ray, 

          Jim Johnson pointed out a couple of years ago that populations of Emerald and/or Black Spreadwings in southwestern Oregon seem to mix green and black (we badly need a cumulative index to ARGIA, so these articles are easier to find, but this one is in the second issue of Volume 18, 2006), and several odonatologists have commented that the two are probably no more than subspecies of the same species. There was no difference found in an analysis of mitochondrial DNA in North American Lestes. No one has made the "official" recommendation to change their status, however, so for now they are still considered separate.
           
          As far as I know, the male in your photo is greener than anyone has reported for lowland California Lestes stultus, and I would call it Lestes dryas without hesitation. Jim found both types together in Oregon, with everything in between, and postmortem color change from one type t o the other sometimes occurs. Geographic variation in odonate species is still poorly documented, but this may be an example. It would be nice to have an official proposal, backed up by data, to combine these two species.
           
          Dennis
           
          On May 7, 2010, at 7:17 PM, Ray Bruun wrote:

          I was out photographing with Rob Santry today. We ha d many Black 
          Spreadwing at Volonte Park in Anderson, Shasta County. At least I 
          thought they were Black Spreadwing. Most are young or teneral with a 
          bronze look. See this photo of a young female taken last weekend at the 
          same spot - http://www.flickr.com/photos/bruunphoto/4572841048/sizes/l/

          But I photographed a spreadwing today, a young male, that is green, like 
          Emerald Spreadwing. I've never seen Emerald Spreadwing in the 
          Sacramento Valley proper, only in the mountains. Nor have I seen Black 
          and Emerald together. The green male can be seen here - 
          http://www.flickr.com/photos/bruunphoto/4587560449/sizes/o/

          Any thoughts as to ID of these two spreadwings?

          Ray Bruun
          Shingletown, Shasta County, CA

        • Jim Johnson
          Just for reference or curiosity s sake, here are a couple shots of Lestes stultus (Black Spreadwing) in southwestern Oregon (in Josephine County about 16 miles
          Message 4 of 7 , May 9 9:49 AM
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            Just for reference or curiosity’s sake, here are a couple shots of Lestes stultus (Black Spreadwing) in southwestern Oregon (in Josephine County about 16 miles from the California border): http://odonata.bogfoot.net/photo-pages/Lestes_stultus.htm . I have some L. dryas (Emerald Spreadwing) shots from other regions for comparison here: http://odonata.bogfoot.net/photo-pages/Lestes_dryas.htm .

             

            The two Lestes stultus were at the same little marshy pond on the same day. Both individuals have the pale, thin (but noticeable) humeral stripe which seems to be characteristic of L. stultus, but I have seen a small number of mature male L. dryas with that too (though admittedly a bit thinner). The green individual isn’t quite as shiny and metallic as L. dryas often are, but you do see dryas that aren’t too different. He also may be a bit less mature than the dark individual since he doesn’t have much pruinescence at the base of the abdomen (but there is plenty at the tip).

             

            I have also found Lestes stultus near Drain, Douglas County, about 115 miles north of the California border and, most interestingly, what seemed to be L. stultus in the Coast Range of northwest Oregon about 200 miles from the California border (Polk County). These latter individuals were at about 870 m elevation on the date of 17 September 2000. The higher elevation and late date seem atypical for L. stultus, but it also makes sense that a species which is early and at lower elevations in the southern part of its range could be found later an at higher elevations further north. In life these individuals were as dark as the dark L. stultus on the link above, but after acetoning they all turned as green as any L. dryas. I wish I had photos of these in life for the comparison, but I wasn’t a photographer at the time. My specimens show a mixture of humeral stripes from quite bold to nonexistent.

             

            Also what’s interesting is that I had visited the northwest Oregon site earlier in the season on 25 June and there were loads of what I presumed were Lestes dryas out. There were lots of tenerals, but the ones that appeared mature didn’t seem unusual at all. This makes me wonder if the Coast Range of northwest Oregon is a true blending area for L. stultus and L. dryas rather than the lower areas of southwest Oregon. And perhaps at that elevation and latitude, the phenology is reversed with L. dryas the earlier species and L. stultus the later one. I should also add that I did not see any green Lestes on the late date when I found the dark ones.

             

            I keep meaning to get back to the Coast Range site, if possible, but it is on private timberland which changed hands a few years ago (from Willamette Industries to Weyerhaeuser). The Nature Conservancy had some sort of agreement with Willamette for surveying, but I don’t know if they still have access with Weyerhaeuser. I’ll have to check on that this year.

             

            Jim Johnson

            Vancouver, Washington

            Jt_johnson@...

            http://odonata.bogfoot.net/

             

             

            From: CalOdes@yahoogroups.com [mailto:CalOdes@yahoogroups.com] On Behalf Of Dennis Paulson
            Sent: Sunday, May 09, 2010 7:00 AM
            To: Cal Odes
            Cc: nw_odonata@yahoogroups.com
            Subject: Re: [CalOdes] Black Spreadwing ID Help

             

             

            Thanks for that info, Steve.

             

            That would seem to indicate that Black Spreadwings can be green, perhaps anywhere in the range of the taxon, and the presence of those green individuals shouldn't influence our decision about the specific status of Black vs. Emerald. That's a step forward, in my opinion. Jim Johnson's findings were in an area in southwestern Oregon where you might expect the two to meet, so the intermediacy of populations there, if those really are intermediate populations (not just variation in either of the species), wouid be more relevant.

             

            A number of other usually brown/bronze metallic spreadwings can look quite green, especially on the abdomen (e.g., Lyre-tipped). Whatever structural aspect of the cuticle is giving them that shiny look, it may be very similar in the green mode and the bronze mode. We still need that study, and I would guess late May/June would be a good time for a spreadwing transect from the Sierras to the Central Valley and from central Oregon south to northern California. How about a moving Blitz, or a concerted county-by-county effort by a bunch of people? The fun thing about any such survey is that you always make additional discoveries.

             

            Dennis Paulson

            Seattle, WA

             

            On May 8, 2010, at 10:01 PM, Steve Rottenborn wrote:



            Inspired by Ray's photo and Dennis's comments, I visited Rosendin Pond near Morgan Hill (Santa Clara County) this afternoon, as I had photographed some greenish Black Spreadwings here last May.  Today I found 400+ spreadwings, including many tenerals around the pond and somewhat more mature individuals throughout the grass and scrub surrounding the pond.  Numerous immature males were extensively green on the dorsal surface of the abdomen, and many of these showed varying degrees of greenish iridescence on the  thorax as well.  However, only 1-2% were noticeably bright green on the thorax, similar to the one Ray photographed.  I posted five photos of two such individuals in the folder "Santa Clara Co. Black Spreadwings" on the CalOdes site.  The brightness of the green on the thorax varied considerably depending on the angle at which I viewed these individuals; much of the time they appeared bright green, but bronzy tones appeared at certain angles.  Around 2-3% of males I saw were mature enough to show pruinosity on the proximal and distal abdominal segments; these showed no green tones on the thorax, but they showed some greenish iridescence on the abdomen.

            Taxonomic uncertainty regarding the relationship of Emerald and Black Spreadwing notwithstanding, the variability present at Rosendin Pond must represent variability in what we currently consider to be Black Spreadwings, based on both range and on the fact that I've never seen a mature male Emerald Spreadwing (which should be conspicuous) at this location.  My photos are not as good as Ray's, but those few bright individuals looked every bit as green as the one Ray photographed (this is best shown on the photo "Black Spreadwing1a").

            I focused on spreadwings so did not note everything else at the pond, but I did see my first Red-veined Meadowhawk of the year, in addition to Cardinal and Variegated Meadowhawks.

            Steve Rottenborn
            Morgan Hill, CA

             

             

            From: CalOdes@yahoogroups.com [mailto:CalOdes@yahoogroups.com] On Behalf Of Dennis Paulson
            Sent: Saturday, May 08, 2010 7:49 AM
            To: Ray Bruun
            Cc: Cal Odes
            Subject: Re: [CalOdes] Black Spreadwing ID Help

             

            Ray, 

            Jim Johnson pointed out a couple of years ago that populations of Emerald and/or Black Spreadwings in southwestern Oregon seem to mix green and black (we badly need a cumulative index to ARGIA, so these articles are easier to find, but this one is in the second issue of Volume 18, 2006), and several odonatologists have commented that the two are probably no more than subspecies of the same species. There was no difference found in an analysis of mitochondrial DNA in North American Lestes. No one has made the "official" recommendation to change their status, however, so for now they are still considered separate.

             

            As far as I know, the male in your photo is greener than anyone has reported for lowland California Lestes stultus, and I would call it Lestes dryas without hesitation. Jim found both types together in Oregon, with everything in between, and postmortem color change from one type t o the other sometimes occurs. Geographic variation in odonate species is still poorly documented, but this may be an example. It would be nice to have an official proposal, backed up by data, to combine these two species.

             

            Dennis

             

            On May 7, 2010, at 7:17 PM, Ray Bruun wrote:

            I was out photographing with Rob Santry today. We had many Black 
            Spreadwing at Volonte Park in Anderson, Shasta County. At least I 
            thought they were Black Spreadwing. Most are young or teneral with a 
            bronze look. See this photo of a young female taken last weekend at the 
            same spot - http://www.flickr.com/photos/bruunphoto/4572841048/sizes/l/

            But I photographed a spreadwing today, a young male, that is green, like 
            Emerald Spreadwing. I've never seen Emerald Spreadwing in the 
            Sacramento Valley proper, only in the mountains. Nor have I seen Black 
            and Emerald together. The green male can be seen here - 
            http://www.flickr.com/photos/bruunphoto/4587560449/sizes/o/

            Any thoughts as to ID of these two spreadwings?

            Ray Bruun
            Shingletown, Shasta County, CA

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