HABITS OF THE VARIOUS SPECIES INVESTIGATED. 5 
I]. HABITS OF THE VARIOUS SPECIES INVESTIGATED. 
At first thought it may seem aside from the main problem to discuss such 
details, but successful work can be done only after learning the habits of 
these insects. Not being familiar with the subject at the start, the results 
given here are the outgrowth of four summers of personal experiences in the 
field, and it is hoped that they may be useful to others who may be led to 
undertake similar work. A recent paper by McDermott* is in practical 
agreement with the experiences herein described. 
The insects were caught by means of a net made of white cheesecloth 
attached to a light wooden handle about1.5 meters long. The whiteclothis 
easily seen and avoided by theinsects, butitis more easily handled in the dark. 
The habits of the Photuris pennsyluanica are markedly different from the 
various species of Photinus. he Photuris inhabits damp ground along’ 
wooded brooks and rivers, and in the daytime it seems to rest in the trees 
as well as in the grass, from which it does not emerge untilafter it has become 
quite dark. It flies high, at great speed, gives a quick flash, and the next 
moment may be repeating the flash 10 to 20 meters away. ‘The color of 
the light is a rich bluish-green. Because of the darkness, it usually is 
impossible to see these insects except when they flash. At times, however, 
when in flight, a faint glow is visible which is easily followed with the net. 
Late at night they become more quiet and often may be found, flashing, on 
grass stems and on golden-rod. When struck to the ground, they run about 
flashing violently (just the opposite from the Photinus) and hence are easily 
located. Late in the season they seem to rest, without flashing, among the 
underbrush. Many specimens were caught by beating the brush and taking 
advantage of their flashing when disturbed and on the ground. 
One compensation for the difficulties in catching the Photuris was in find- 
‘ng that they are strong and hardy, not being easily crushed; and that they 
could be kept for days in large glass beakers (12 X18 cm.) containing clean 
moist sod, the top being covered with cheesecloth. ‘They are carnivorous, 
2zating their dead comrades. In captivity they kill and eat the Photinus. 
The Photinus pyralis are not so easily kept, but are more plentiful and more 
2asily obtained. In the previous work on the latter, they were caught and 
che photographs made the same night. In the present work, half the night 
was spent in catching the Photuris, and usually the photographing of the 
ight was done in a dark room on the following day. 
In the Photuris the light organs of the female are almost as large as those 
xf the male. The females outnumber the males by about 15 to 1, so that 
me catches but few of the latter. 
The Photinus pyralis is plentiful everywhere in this locality. It comes 
nut at dusk, when it can be seen and easily caught. It flies low, hovers 
ibout the grass, apparently searching for the female. ‘This species is more 
lelicate than the Photuris, is easily injured, and is not so easily kept in 
captivity. The light organ in the female is very small, and from her habit of 
‘emaining in the grass, occasionally flashing, and from the fact that the males 
yutnumber the females by about 15 to 1, the captured specimens of this species 
vere mostly males. The flash is a long fulmination of yellowish light. 
*McDermott, Canadian Entomologist, Nov. 1910. 
