36 Psyche [April 



THE LUMINOUS ORGAN OF THE NEW ZEALAND 

 GLOW-WORM.i 



By W. M. Wheeler and F. X. Williams. 



The earliest description of the New Zealand glow-worm seems 

 to be given in a brief note by Meyrick published in the Entomolo- 

 gists' Monthhj Magazine for 1886. This observer found a number 

 of larvae, which he supposed to be those of a Staphylinid beetle, 

 on the damp, precipitous banks of a densely shaded creek near 

 Auckland. The larvae were described as burrowing "in the earth, 

 exposing the head and anterior portions from the burrow but having 

 in front of them a sort of irregular slimy network. " They occurred 

 in such numbers that more than fifty were counted in a square 

 foot of surface. Meyrick states that the same or a similar species 

 has been noticed in caves and mines in other parts of New Zealand. 

 He says that "the light consists of a small light-greenish white 

 erect flame rising from the back of the neck, " and that the food of 

 the creature consists of minute insects probably attracted by its 

 light. 



During 1886 and 1887 Hudson published accounts of the insect 

 and pointed out several errors in Meyrick's description. He 

 showed that the luminous larva is not so numerous in a given area, 

 that its light does not proceed from the neck but from a large 

 glutinous knob at the posterior end of the body and that it inhabits 

 irregular cavities in the earthen banks "where it hangs suspended 

 in a glutinous web, which also appears to envelop the body, 

 large quantities of sticky mucous being periodically shot out of 

 the mouth of the larva and formed into threads as required." 

 Hudson supposes that the larva feeds on decaying vegetable 

 matter. He saw the light displayed most brilliantly at 3 or 4 

 o'clock in the morning but on several occasions observed no light 

 all the evening. The light does not serve to attract food but 

 "to assist the larvae in escaping from enemies, as when disturbed 

 they nearly always gleam very brilliantly for a few seconds, sud- 

 denly shutting off the light and retreating into the earth." The 

 imago reared in the breeding cage proved to be a Tipulid fly which 



1 Contributions from ths EntoniDlogical LabDratory, Busssy Institution, Harvard University, 

 No. 86. 



