THE BLACKHEAD FIREWORM OF CRANBERRY. 
17 
often have a light golden-brown sheen. The antennae are about one- 
half the length of the body and more or less bristlelike. 
The adults live from 3 to 33 days after they emerge, and during this 
time eat little or nothing, except, perhaps, a little nectar from the 
blossoms, or water in the form of clew or rain. 
Habits of Flight. 
After the moth emerges from the pupal case it rests for a short time, 
during which the wings are spread and dried. It then starts to fly 
and moves rather swiftly in a short, jerky, darting motion, making 
usually only short flights from place to place over the vines. Par- 
ticularly on heavily infested bogs the moths are very conspicuous for 
their habits of flight. 
They will often be seen 
to rise in large numbers 
when disturbed, as by 
spraying or by a person 
walking through the 
vines on a warm after- 
noon, suggesting to some 
the appearance 
cloud. 
of 
Fig. 9. — The adult or moth at rest on a cranberry up- 
right. Enlarged about 6 times. 
Periods of Activity. 
A few moths may 
generally be seen flying 
from tip to tip almost 
every hour of the clay 
from the time of their 
first appearance in June 
until late in September 
and October, but the time of day they are most active is from aoout 
3 o'clock in the afternoon until after dusk. During this period, 
especially if the weather is warm, they may be seen to rise in the air 
for a few feet, making their characteristic short, jerky flights. 
Migration. 
It is in the moth stage principally that the blackhead fireworm 
spreads itself over the bog or invades an adjoining one. The moth, 
however, flying only short distances, would not naturally migrate 
more than several yards from its original region of activity; but, 
helped by the wind, it is possible for it to be carried as far as several 
74890°— 22 3 
