45 



Meyrick records finding a luminous Dipterous larva in New 

 Zealand on the steep earthy banks of a creek. Mr. G. V. Hudson 

 in a further note (" Ent. Mo. Mag.," vol. 23, p. 99) states that the 

 insect inhabits irregular cavities in the bank, where it hangs, sus- 

 pended in a glutinous web, which also appears to envelop its 

 body. The light in this case proceeds from a large glutinous knob 

 situated at the posterior extremity of the larva. He suggests that 

 the light may assist the larva in escaping from enemies, as when 

 disturbed the}' nearly always gleam very brilliantly for a few 

 seconds afterwards, then suddenly shut off the light and retreat into 

 the earth. A fly bred from one of these larvae turned out to belong 

 to the Mycetophilid genus Tn'iiiiera. 



The fly Thi/ieo])Jioia ri/noj)hila, which is metallic- blue with a large 

 orange-red head, is said to be nocturnal in habit and to feed on 

 dead bodies by the light of its phosphorescent head (see " Entom. 

 M. M.," vol. 15, p. 43). 



^Ye have also records of luminosity in two species of Ephemeridte, 

 Telof/anndes tristis, and Ccenu dhiiidiata ; in certain Termites ; in 

 some Australian ants, Iridomyrmex detects : and in some hairy 

 lepidopterous larvae from Parana supposed to belong to the family 

 Nymphalidae. These larvae also possessed very violent urticating 

 properties. 



To sum up, nearly all the cases of luminous insects, and all those 

 that are in any way well-known and common, belong to the order 

 ■ Coleoptera, and even here almost entirely to the famil}" Lampyridte. 

 An exception to this statement is found in the elaterid genus 

 PyrupJionis, but other records all require confirmation. In the 

 Lampyrid^e the light plays an important part in securing the 

 mating of the sexes, but its functions in other luminous beetles have 

 not been satisfactorily' explained. 



In other Orders of Insects luminosity is rarely met with, at any 

 rate in the normal condition of health ; little or nothing is known 

 of the part that it plays in the life of the animal, indeed its very 

 existence apart from what we may call accidental causes, is usually 

 more or less problematical. 



