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FLORIDA ENTOMOLOGIST 
Official Organ of The Florida Entomological Society, Gainesville, 
Florida. 
ORE SW ATSONE. 2: ee: Sao ee nae nt pode ee Editor 
WAIEMON | NE WEG 2 ee ek ee Associate Editor 
sa WSG es Degghl 6 Of gO) sence mea ai Sa ceo ara ger a al Business Manager 
Issued once every three months. Free to all members of the 
Society. 
Subscription price to non-members is $1.00 per year in ad- 
vance; 35 cents per copy. 
SOUTHERN MIGRATION OF BUTTERFLIES 
FRANK STIRLING 
Not in many years has the southern migration of the Great 
Southern White, or Gulf Butterfly (Pieris monuste L.), been 
quite so great or noticeable as during the early part of June of 
this year (1923). Their numbers along the waterways of the 
east coast of Florida, especially along the Halifax and Indian 
Rivers, were so great that the radiators of automobiles driving 
north and south became thoroughly plastered with them. The 
migration is constantly southward and one wonders where this 
tremendous army comes from. It seems that they are first noted 
in large numbers in the vicinity of Titusville and as one travels 
southward their numbers seem to increase until they reach un- 
limited millions between Fort Pierce and Stewart, with an ap- 
parent increase in numbers as they advance southward. Always 
they are noted as flying thickest along the edges of the water, 
such as the two rivers above mentioned, Lake Worth, the East 
Coast Canal and Biscayne Bay. There they apparently leave the 
mainland and follow the Gulf Stream to no one knows where. It 
is not unlikely that these butterflies begin to make up the bulk 
of their army in such states as the Carolinas and Georgia, for 
they have been reported in the vicinity of Jacksonville, Florida, 
on their journey south. 
It is observed that numbers of these butterflies occur some 
three to five miles west of the inland waterways and are always 
flying eastward, apparently for the purpose of joining the main 
army in the southward flight. It is not unlikely that many of 
these butterflies breed and hatch in certain portions of the swamp 
lands and Everglades of the interior; also in farms and fields 
where cabbages and collards are grown. These butterflies, upon 
reaching maturity, apparently follow instictively the eastward 
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