117 
taken at frequent intervals throughout the season of 1891, the 
sexes of which we have separated, it appears that the ratio of 
males to females at lights was 16.5 to 1, and from trees and 
various surface shelters (839 specimens) 1.3 to 1). My data 
on this subject rriav be convenientlv exhibited in the following 
tabular form: 
Species. 
Dates. 
At Light. 
On Tkees, etc. 
No. of 
Specimens. 
Ratio of male 
to female. 
No. of 
Specimens. 
Ratio of male 
to female. 
fusca. 
Apr. 18—June 4 
94 
2.2 
193 
1.3 
hirticula. 
Apr. 29—June 24 
185 
4.G 
352 
1.3 
inversa. 
Apr. 29—June 28 
1,418 
51.0 
271 
1.5 
tri sti s 
May 7 
135 
1 4 
gibbosa. 
May 15—June 24 
42 
13.0 
20 
2.3 
The adult beetles emerging from the ground, flying about at 
night* in search of food, pair in the trees, to which they resort 
in myriads, and retreat again to the earth by day. Their first 
flight is made in the early evening, beginning at dusk, as they 
pass from the ground where they have lain hidden by day to 
the trees on which they feed. With the advent of day they fly 
from the trees to the earth, and hide themselves an inch or less 
underground, or sometimes merely creep under fallen grass and 
other similar shelter. 
Particulars concerning this retreat to their hiding places at 
the dawn of day are given in notes made by Mr. John Marten 
and Mr. Philip Hucke, detailed for night-work on June beetles 
May 19, 1891. 
3:45 a. m. Mr. Hucke reports the occasional dropping of a 
beetle from trees in the artificial forest (chiefly butternuts and 
hickories) where these observations were made. At 4:05, an 
occasional beetle still dropping to the ground without making 
any effort to fly. At 4:10 the air suddenly became full of flying 
beetles. One and then another began to make a buzzing noise 
with its wings, when, as if at a general signal, they deserted the 
trees in thousands, and by 4:25 everything was still again and 
nearly every one was gone. 
Within the woods the beetles flew to a distance from the 
trees about equal to the height from which they started, 
the lower ones on the trees making a somewhat longer flight 
proportionally. Striking against the weeds and undergrowth, 
they folded their wings, and by 4:30 o’clock reached the ground 
within a hundred feet of the trees from which they took their 
flight. Probably in a clearer place they would make longer 
flights. 
* A single species has been observed to fly by day in Utah. (Proc. Ent. Soc. Wash., Vol. 
II., p. 241.) 
