Bruce Spanworm or Winter Moth?

[Steve J]

Found this fellow at my porch light a couple of weeks ago. Upon trying to

ID him I found he could be the invasive Winter Moth (brumata) rather than the

more expected Bruce Spanworm (bruceata)

The USDA map shows that brumata has not reached this far north yet but with

climate change one would think that it would be expanding its range. It was collected at

my porch light on November 14th in USA, Vermont, Franklin County, Bakersfield.

Anyone hazard a guess as to which it is?

[Micahel Sabourin]

Steve,

this would still be Bruce Spanworm

Michael Sabourin

--

---
You received this message because you are subscribed to the Google Groups "Vermont Entomological Society (VES)" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vermont-entomologica...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Bryan Pfeiffer]

Hi Steve,

I passed this along to one of my moth pals, Hugh McGuinness, who suspect that it would require molecular work to be certain. Hugh's not even sure that dissection and a look at the genitalia would help. He writes:

As far as I know, you can only distinguish them with DNA. The specimen could probably be sent to Joe Elkington's lab at UMASS for determination, however, the specimen might end up destroyed.

Best,
Bryan

--

---
You received this message because you are subscribed to the Google Groups "Vermont Entomological Society (VES)" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vermont-entomologica...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

--
br...@bryanpfeiffer.com
http://www.bryanpfeiffer.com

[Steve J]

Thanks Bryan

I suppose if it is the invasive brumata that doing the analysis would be of some use as my location is quite north of the USDA map for that species. It would certainly be yet one more climate warming indicator which might be of interest to someone. Michael Saborin is saying it is Bruce Spanworm but I'm not sure how he is differentiating it from brumata.

Thanks for your response.

Steve

On Tue, Nov 22, 2016 at 8:10 PM, Bryan Pfeiffer <br...@bryanpfeiffer.com> wrote:

Hi Steve,

I passed this along to one of my moth pals, Hugh McGuinness, who suspect that it would require molecular work to be certain. Hugh's not even sure that dissection and a look at the genitalia would help. He writes:

As far as I know, you can only distinguish them with DNA. The specimen could probably be sent to Joe Elkington's lab at UMASS for determination, however, the specimen might end up destroyed.

Best,
Bryan

On 11/22/16 8:49 AM, Steve J wrote:

Found this fellow at my porch light a couple of weeks ago. Upon trying to

ID him I found he could be the invasive Winter Moth (brumata) rather than the

more expected Bruce Spanworm (bruceata)

The USDA map shows that brumata has not reached this far north yet but with

climate change one would think that it would be expanding its range. It was collected at

my porch light on November 14th in USA, Vermont, Franklin County, Bakersfield.

Anyone hazard a guess as to which it is?

--

---
You received this message because you are subscribed to the Google Groups "Vermont Entomological Society (VES)" group.

To unsubscribe from this group and stop receiving emails from it, send an email to vermont-entomological-society+unsub...@googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

--
br...@bryanpfeiffer.com
http://www.bryanpfeiffer.com

--

---
You received this message because you are subscribed to a topic in the Google Groups "Vermont Entomological Society (VES)" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/vermont-entomological-society/QKrSSzEY6-k/unsubscribe.
To unsubscribe from this group and all its topics, send an email to vermont-entomological-society+unsub...@googlegroups.com.

[Bryan Pfeiffer]

Yikes! Disagreement on Operophtera between the two moth authorities I hold in the highest regard: Hugh and Michael. Is there no certainty to this world? :-) Well ... not really. In any event, here's something on what I called bruceata (including a video):

http://bryanpfeiffer.com/2014/11/10/fertility-and-flight-in-a-winter-moth/

Best,
Bryan

To unsubscribe from this group and stop receiving emails from it, send an email to vermont-entomologica...@googlegroups.com.

For more options, visit https://groups.google.com/d/optout.

--
br...@bryanpfeiffer.com
http://www.bryanpfeiffer.com

[Steve J]

Thanks for the info and video. Bryan. That was fun.

I should have mentioned that the moth I collected has a wingspan of 29mm (pinned), quite a bit smaller than the 1.5 inches mentioned elsewhere but Peterson puts the Bruce at 25-30mm (at rest, I assume). The moths in the video seem larger but it is hard to tell.

Steve

[Kent McFarland]

I was too under the impression that these moths are nearly impossible to differentiate. This is from the NY Dept. of Ag., summing it up nicely. 

Two papers published provide illustrations and descriptions of the genitalia of winter moth and Bruce spanworm (Eidt et al. 1996, Troubridge and Fitzpatrick 1993). Characters described by Troubridge and Fitzpatrick for distinguishing the two species, such as a black dot on the hindwing of the Bruce spanworm [see photo left], are not reliable and are usually obscured on specimens that have been captured in sticky traps. Dissection of the male genitalia provides a means to differentiate the two species. After dissecting over a thousand potential winter and Bruce spanworm moths from the New England states, Jeff Boettner (Elkinton Lab-U-Mass) has found the distinction between the two species to be less clear cut than the published illustrations. He examined the “uncus” for three characters: 1) general shape, 2)measurement at the tip of the uncus and 3) measurement at the widest point of the uncus. 

I do wonder if females can be. Apparently Bruce has no vestigial wings, or very very small. While Winter has vestigial wings that are readily apparent. Not sure if this holds and is true. Anyone? Here's a couple of macros from Woodstock, VT of mating pair. 

http://www.kpmcfarland.com/Wildlife/Moths/i-H93hBnh/A

http://www.kpmcfarland.com/Wildlife/Moths/i-sKtJjkC/A

Kent

____________________________

Kent McFarland
Vermont Center for Ecostudies
PO Box 420 | Norwich, Vermont 05055
802.649.1431 x201