Phoebis sennae migration (longish)

[Richard Worth]

Hi Robert,

One person to contact is Dr. Tom Walker at the Univ. of Florida.  He 
has done some research on this very topic.  E-mail him at: 
TJW at gnv.ifas.ufl.edu
or the U. of F. web site is at:
http://www.ifas.ufl.edu/~entweb/entomolo.htm
Hit "About our people" to get to e-mail


Some of his published papers can be found in the jounals  "Florida 
Entomologist" and "Jour. of the Lepid. Society".  I'm sorry I don't 
have the exact references in front of me, and I can't remember the 
specifics of the studies.  In addition to P.sennae, he has also 
tracked the movements of the Gulf Frit., Long tailed skipper and 
buckeye in Florida.

Hope this helps a little,  Rich




>Hello,
>
>Bob Augustine sent this to me to post to this list.  I have broken it up
>into two segments.  He and I are interested in replies--I'm interested in
>this phenomenon too but haven't researched it.
>
>Thanks,
>
>Rob Hilton
>robert at csa.com
>Bethesda, MD
>
>+++++++++++++++++++++++++++++++++++
>The Mystery of the Cloudless Giant Sulphurs (Phoebis sennae)
>
>Has anyone reported Cloudless Giant Sulphurs heading north? I have
>contended for years that their movement is southbound only, contrary to
>most books, and I have yet to meet anyone who has actually seen one
>definitely going north.
>
>Even if one Phoebis sennae was seen in Washington heading north, it may
>have been doing so merely to follow a bend in the river or an attractive
>scent and may not have continued in that direction once it was beyond the
>observer's view. Moreover, to create the sort of southbound flows that have
>been seen many, many, sulphurs_not one or two_would have to have moved
>north. There is no evidence whatsoever of any such movement ever taking
>place around here (Washington). Most authors of lepidoptera literature
>covering the middle Atlantic states omit the species altogether.
>
>The reports from Folly Island, SC (near Charleston) from 1978-1980 (Aug.
>24-Oct. 9) of as many as 125-323/5 minutes going NE are intriguing. At that
>location, NE is exactly the direction of the coastline as far as Cape
>Hatteras, NC. One wonders what happened when they got that far. If it
>weren't for the reports from Florida, I'd be tempted to say perhaps they
>flew on out to sea NE from Hatteras. Where _did_ they go? That's the kind
>of flight we should have witnessed every summer that was followed by a big
>southbound flight. (Could such a movement at such dates be responsible for
>new broods heading south so soon afterward?) Where did the Florida
>butterflies go?
>
>I recall seeing similar numbers of these "flying Post-it Notes" streaming
>off from Point Lookout, MD toward Cape Charles on peninsular Virginia (I've
>no doubt some stopped in at Smith Island, but I'll bet they moved on from
>there, as in Florida, heading SSE) on 10 Oct. 1987 across many more miles
>of open water than the easier trip to the more southerly, nearby west shore
>of the Chesapeake Bay in Virginia. Until that point, I had believed the
>species--or at least its movements--were all coastal. But Point Lookout is
>many (about 50) miles inland, and there were more there than at coastal
>locations of similar latitude such as Chincoteague and Ocean City. Clearly,
>they were coming from somewhere inland.
>
>I saw a similar flight at Point Lookout in 1998 and traced it all the way
>back to Route 50, the main E-W route between Washington and
>Annapolis--mostly following the Patuxent River. Some were seen even further
>north. That year eggs and caterpillars of Phoebis sennae were found at Cape
>May and elsewhere.
>
>Where do all these butterflies go? Not so many years ago we were asking
>that about Monarchs, and the question turned out to have a surprising answer.
>
>The little research I've done on this intrigues me further. Did you know
>that a number of related species also have northward movements like those
>alleged to occur with Phoebis sennae? The final paragraphs in the species
>accounts of the (1981) Audubon Society Field Guide to North American
>Butterflies make for some fascinating reading (emphasis added):
>
>"Like the White Angled Sulphur [Anteos clorinde], this high-flying species
>[Yellow Angled Sulphur--Anteos maerula] engages in northern emigrations
>that occasionally send some into the United States."
>
>"Statira [Aphrissa statira], along with some species of Phoebis, takes part
>in immense flights _out to sea_ from South America. Unlike the Cloudless
>Giant Sulphur, Statira exhibits no such mass movements in North America,
>and in fact is considered rather an uncommon resident species."
>
>
>--Bob Augustine raugustine at tms-hq.com

Richard A. Worth
Oregon Department of Agriculture
Plant Division
rworth at oda.state.or.us
(503) 986-6461