|Lightening bug- Shelly Cox|
|Fireflies at night- Click to enlarge JuddPatterrson.com|
|Ventral view- Firefly.org|
Our common fireflies rest during the day, then come out at night, the female sticking to the low lying grass and shrubs, sending out her Siren call. Meanwhile we are more likely to focus on the male who patrols, looking for the special flash of the female of his species. When he finds the signal he drops down to do his thing.
Actually, the first theory concerning their light was that it was an aposematic warning, a bright color saying "Don't eat me, I taste bad." In fact they do have distasteful chemicals which may not help the victim but will help its classmates in the future. Only later did the sexual signaling become apparent.
Females of the genus Photuris are the Mata Hari's of the family Lampyridae, mimicking the mating flashes of other firefly species to lure them for nefarious purposes. The excited male lands for a tete-a-tete, only to be eaten by this femme fatale of fireflies. As it is also with many spiders, sex is a risky proposition.
A few days after mating, a female will lay her eggs on the ground and a few weeks later the larvae emerge and start to feed. This will continue through the late summer and as the "glow worms" grow larger through successive instars, their light becomes more obvious on moonless nights.
September is the time to see the product of all those flickering summer nights. The gravel along the edge of Bull Creek starts to light up with faint luminescent spots of light, not the flash of a firefly but the subtle slow wink of its larvae, the glow worms. Collecting them is tricky as they are moving along leaf-litter, frequently disappearing from view. Their light is weak and brief, and I lose my night vision when I turn on a flashlight to capture the critter.
|Ventral view of larva- note jaws- Click to enlarge|
|Larva rolled up in defensive position|
|Larval green light- Davidson.edu|
Firefly.org has lots of practical information on fireflies and their diminishing populations.
Detailed scientific information on fireflies is at this MDC site.
More than you may want to know about raising fireflies is at this link.