256 ENTOMOLOGICAL SOCIETY 
NOVEMBER 12, 1889. 
Twenty-two persons present. President Schwarz in the chair. 
Mr. F. M. Webster, of Lafayette, Ind., and Dr. John Hamil- 
ton, of Alleghany, Pa., were elected corresponding members. 
Mr. Hbward exhibited specimens of Xylonomus rileyi, Ashm. 
(Ichneumonidce} , recently captured resting on the shady side of 
the Washington Monument. Mr. Lugger said that he has found 
this species in Michigan, and Mr. Marlatt that he had found it in 
Kansas. 
Mr. Lugger related his observations on the migrations of Da- 
nais archippus in Minnesota, and has since furnished the follow- 
ing abstract of his remarks : 
ON THE MIGRATIONS OF THE MILKWEED BUTTERFLY. 
By OTTO LUGGER. 
I have observed the Milkweed butterfly {Danais archippus} carefully for 
the last two seasons in Minnesota. In 1888 the spring was very late. I 
observed large numbers of these insects flying at St. Anthony Park on 
May 28. No traces of any milkweeds were visible at that time. All the 
specimens looked bleached and had but few scales upon their wings, which 
were almost- transparent ; yet very few specimens had their wings torn in 
any way. They flew about rapidly, evidently in search of food, which at 
this time was scarce, consisting of the honey in the flowers of wild cherries 
and plums. On June 5 specimens had arrived at Perham, some two hun- 
dred miles northwest of Minneapolis. Isolated specimens were observed 
there on June 3 and 4, but the butterflies were quite numerous a few days 
later, after which they disappeared. They also fed upon the honey of the 
cherries and plums. On June 17 I found numerous specimens in St. An- 
thony Park in the act of mating, and found also three eggs upon the first 
small leaves of the Asclepias. On J une 24 I found numerous specimens at 
Fargo, Dakota, in the act of mating. In July, in Perham, very large num- 
bers mating; in fact, but very few single butterflies could be found at this 
date. The males carry the females (or, perhaps, the other way) for a very 
long time. On July 18 larvae could be found everywhere upon the plants 
of Asclepias growing near Perham. 
The season of 1889 commenced early, and the butterflies arrived at Fer- 
gus Falls (in the Red River Valley) as early as May 2, and they were seen 
mating on May 26. In this case also the butterflies followed the flowering 
season of wild cherries and plums. As soon as these flowers cease to 
bloom the insects disappear, but can be met with again farther north, where 
these plants are then just beginning to flower. 
I think the peculiar pockets in the hind wings of the males are not of 
any sexual importance, but serve another purpose. I frequently saw flying 
