82 INSECT PHYSIOLOGY 



Light is produced when an enzyme 'luciferase' acts upon a sub- 

 strate 'luciferin'. The quantity of heat set free in this reaction is very 

 small ; at least 98 per cent, of the radiant energy appears in the form 

 of light, usually limited to the greenish-yellow region of the spec- 

 trum. In the fire-flies and glow-worms the production of light, 

 whether as a steady glow or as a succession of flashes, is under the 

 control of the central nervous system. The mechanism of control is 

 uncertain: it is sometimes thought to be effected by a system of 

 minute sphincters in the tracheal endings which control the access 

 of oxygen to the light-producing cells. In the luminous beetles the 

 light certainly serves as a mating signal. 



BIBLIOGRAPHY 



beard, r. l. Ann. Rev. Entom., 8, (1963), 1-18 (insect toxins and venoms: 

 review) 



brooks, m. a. Symp. Soc. Gen. Microbiol, 13, (1963), 200-231 (symbiosis 

 in insects : review) 



bursell, e. Physiology of Insecta, I (Morris Rockstein, Ed.) Academic 

 Press, New York, 1964, 323-361 (temperature and humidity re- 

 lations) 



chefurka, w. Physiology of Insecta II (Morris Rockstein, Ed.) Academic 

 Press, New York, 1964, 582-768 (intermediary metabolism) 



cromartie, r. i. t. Ann. Rev. Entom., 4, (1959), 59-76 (insect pigments: 

 review) 



edney, e. b. The Water Relations of Terrestrial Arthropods, Cambridge 

 University Press, 1957, 109 pp. 



gilmour, d. The Biochemistry of Insects, Academic Press, New York, 1961, 

 343 pp. 



house, h. l. The Physiology of Insecta II, (Morris Rockstein, Ed.) Aca- 

 demic Press, New York, 1964, 769-813 (insect nutrition) 



mcelroy, w. d. The Physiology of Insecta I (Morris Rockstein, Ed.) Aca- 

 demic Press, New York, 1964, 463-508 (light production) 



roth, l. m. and eisner, t. Ann. Rev. Entom., 7, (1962) 107-136 (chemical 

 defences of insects : review) 



sacktor, b. The Physiology of Insecta II (Morris Rockstein, Ed.) Academic 

 Press, New York, 1964, 484-580 (respiratory metabolism in 

 muscle) 



salt, r. w. Ann. Rev. Entom., 6, (1961), 55-74 (insect cold-hardiness: re- 

 view) 



wigglesworth, v. b. Tijdschrift Ent., 95, (1952), 63-68 symbionts in 

 blood-sucking insects: review) 



The Principles of Insect Physiology, 6th Edn., Methuen, London, 1965, 



464-495 (nutrition); 533-562 (chemical transformations and pig- 

 ment metabolism); 562-593 (respiratory metabolism); 594-628 

 (water and temperature relations); 409-413 (light production) 



