Behavioral Ecology

Behavioral ecology is the analysis of behavioral features of the phenotype as ecological and reproductive adaptations. Insect bioluminescence offers remarkable opportunities for applying the "adaptationist's program" of behavioral ecology, observation, speculation, systematic observation, and experimentation, in the laboratory and field. The experimenter can enter these informational transactions with a penlight or computer-driven light-emitting diodes. Further, interactions often occur quickly and can be photographed, videotaped, and electronically recorded for precise analysis.

The mating signals of lightningbug fireflies are the most commonly seen example of insect luminescence, but others are easily found if sought in their habitat: prey-attracting glows of larval Appalachian glowworm flies (O. fultoni) in beds of impatiens at roadside springs and under overhanging mossy banks of streams along dark mountain roads; glowing Arachnocampa luminosa larvae hanging from ceilings of New Zealand caves, attracting midges from streams below and tourists from around the world; and prey-attracting glows of larval termitophageous click beetles (Pyrearinus termitillum-inans), which make termite mounds look like high-rise buildings of a metropolis seen from the air, in the dry-scrub region (open-formation cerrado) of northeastern Brazil.

The significance of many luminosities remains problematic: why do sparkling, galaxy-like arrays of flashing Collembola result when rotting forest litter under damp logs is scratched with a hand cultivator? Is each individual, when stimulated by our invasive touch, warning relatives, or a predator, say, a firefly larva? Several firefly knowns and unknowns are illustrated in Fig. 3, in which black circles, teardrops, stripes, and beads represent emissions of different forms. Coordinates on the axes guide attention to specific locations in the scene—near 3M an armadillo views a flashing firefly under its nose, perhaps retrieving memory data that flashing lights taste terrible or, previously when eaten, vomiting followed. The blood of some fireflies has been found to have cardio-glycosides that can be deadly for some animals. (Recently, to the regret of pet owners, several exotic lizards died after eating North American fireflies.) This fact makes a warning (aposematic) function of luminosity a testable explanation.

The most often seen and best understood bioluminescent emissions are the mating flashes of lightningbug fireflies. Nearly all flying emissions seen afield are the mating signals of males, signaling over and over, advertising, with their species' sexual-recognition flash patterns. The male flash patterns of many species are distinctive and diagnostic in a

FIGURE 3 A graphic scene of firefly emissions, with alphanumeric coordinates to index text discussion. The diagram illustrates flash patterns, response flashes, a warning flash (3N), an attack flash (7E), illumination flashes, a flash pattern default (9D), some (probably?) meaningless flashes of "stressed" fireflies (6J, 7N, 9F), and a Photuris larval glow (8L-10L).

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