By Sachin Chorge
Article submitted on January 2008
Article accepted on February 2008
Bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy. The name originates from the Greek bios for "living" and the Latin lumen "light". Bioluminescence may be generated by symbiotic organisms carried within a larger organism. It is generated by an enzyme-catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidised by the enzyme luciferase. Adenosine triphosphate (ATP) is involved in most instances. The chemical reaction can occur either within or outside of the cell. In bacteria, the expression of genes related to bioluminescence is controlled by an operon called the lux operon.
Many organisms have been described as bioluminescent. Some animal luminescence can be attributed to infection by luminous bacteria, while other animals have evolved luminous organs. Insects with luminous organs occur in Collembola, Hemiptera, Coleoptera and Diptera. Insect bioluminescence has evolved to allow insects to signal mates of the same species at night. Flash patterns and wavelengths of maximum light emitted have been studied. This research has shown that these characteristics of insect light are diagnostically important because they are unique to each species studied. These characteristics of insect luminescence can be used to distinguish bioluminous insect species from each other in the field more effectively than comparisons of surface brightness.
The insect with the brightest bioluminescence is discussed in this report. Surface brightness, or flux emitted per unit area of light organ, is measured in lamberts (. One lambert is equal to one lumen per square centimeter of a perfectly diffusing surface. A lumen is the flux emitted per unit solid angle by a point source of one candela. Many studies have measured the intensity of emitted insect light in candelas, rather than the surface brightness of insect light organs. Luminous intensity is found by determining how many insects it takes to give the same light density as the flame of a standard sperm candle. These measurements cannot be accurately converted to units of surface brightness because measurements of luminous areas are not reported.