38 BULLETIN 885, II. S. DEPARTMENT OF AGRICULTURE. 
growth throughout the day. The following is the procedure as 
observed in the laboratory on July 12, 1919: At 2.30 p. m. a number 
of young shoots on which a large number of adult males and females 
had gathered were brought in. The females were in the majority, 
there being about 5 females to every 2 males. These were carefully 
observed from 2.30 until 5 p. m. and copulation between at least 20 
males and females (40 individuals) was witnessed. The males were 
found to rest beside the females with their bodies parallel to those of 
the females. Occasionally two males were found one on either side 
of a female. At intervals a certain nervous fluttering of the wings 
of the males was seen. This was carefully watched. 
Beginning with a male resting beside a female, both acting nor- 
mally, the following observation was made: The males would rest 
quietly beside the females for from three to five minutes. Then 
they would begin fluttering their forewings slowly and rhythmically 
at first. This fluttering of the wings continued with increasing in- 
tensity until it was very violent and consisted of very short rapid 
jerks, the forewings extending forward over the thorax and head of 
the insect at an angle of 120 degrees. Sometimes they stood straight 
up at an angle of 90 degrees to the body. The hindwings sometimes, 
though not always, were held rather close to the body and never 
more than an angle of 15 degrees away from it. In the height of 
this very rapid wing vibration there was a sudden pause with the 
wings extended forward. Then with an exceedingly rapid and sud- 
den jerk the male thrust his abdomen under the normally resting 
wings of the female and the connection was made, apparently by the 
female being ready to receive the male and by moving the end of 
her abdomen into the proper position simultaneously with the male. 
The trembling movement lasted from 25 to 45 seconds and the mat- 
ing lasted from 40 to 50 seconds. During the time that the male was 
going through his preliminary movements, the female was passive, 
except that she would occasionally and irregularly give her wings a 
sharp sudden jerk, and move her legs, especially those on the side 
by the male. This movement was very inconstant. 
Two males were observed trying to mate with the same female, 
though only one was successful, in contrast to what has been ob- 
served in Calopteron juvenile Gorh., a lampyrid beetle, where five 
males have been found mating with the same female. A male has 
also been observed to mate with the same female three times in 20 
minutes, and another male was seen to mate with three compara- 
tively widely separated females in the course of hall an hour. 
Mating has been observed between individuals whose coloration 
would indicate that they were not more than 12 hours old. It has 
also been observed that if a female would move during the preliminary 
stages of the mating the male would wander about aimlessly in search 
