OUR GLOW WORMS.

Poverty Bay Herald, Volume LII, Issue 16975, 5 March 1926, Page 5

OUR GLOW WORMS.

THEIR WONDERFUL LIGHT

INTERESTING RESEARCHES.

(Special to the Herald.)

qiRISTCUURCR. this day. ■ Mr. A. Tonnoir, entomologist at the, Canterbury Museum, lias begun some interesting researches into New Zealand's glow worms. Ho has returned to Christchurch from a visit, to North Island, eaves in which those insects Jive. Amongst them arc the Waitomo Caves, "the heavenly splendor of which)" he states, ''cannot bin- silrpaa'sscd b"y any others."

Thanks to the obliging help of Mr. Cook, manager of the eaves, Mr. Tonnoir has been able to bring back from Waitomo several hundred live glow worms, which are now spinning their webs on the cement roof of an underground tunnel specially prepared for them in tho Canterbury Museum grounds. These specimens, which he intends to keep under closo observation, will help him to solve many points of' their life history, and chiefly to make researches into the nature and the mechanism of their wonderful light. NOT A REAL WORM. Tn an interview Mr. Tonnoir explained that the New Zealand glow worm is the lava, of a fly of the ' fungus gnats family (myectophilid) and not a real worm. It has nothing in common, except the glowing light, with the European glow worm. Which also is not a worm, but fhn wingless female of a. larnpirid beetle. "The ecodogieal conditions in the Waitomo eaves are absolutely ideal for glow worms," he said. "The air is saturated with moisture, which they absorb through their skins and are thus provided with; am abtindaitf,, supply of liquid, which.'allbws them to spin numerous long hanging threads. The perfectly still atmosphere of the cave .allows the threads to be spun in large numbers without intermingling with each other, as they would do if submitted to the action of a draught or wind. For the same reason, the "thread can reach a much longer size and thus increase tho chance of catching prey. A very abundant supply oi' suitable food is pro vided for' fheni b v the stream flowing slowly through the eave, the bed of which is exceedingly rich in mud containing- a large percentage of organic matter, upon, which millions of midges larvae are feeding. These larvae soon transform into, little flics, which on emerging from the water are attracted to'the roof of the cave by the light of the glow worms and soon fall victims in their snares. Thus the abundant supnly of food accounts for the hundreds of thousands of glow worms of the Waitomo caves. In fact, their number is limited only by the roof space above the river. LIFE OF THE GLOW WORM. ''The duration of the life of the, glow worm depends on its supply of food. As an average it can be said'to last several months. When it has reached its full size all the hanging threads are reabsorbed, and for the first time in its life the worm leaves its main thread to hang down from it and then changes into a pupa or chrysalis, which Lists only a few days and is also luminous. It does not take any food during that stage. The fly winch emerges from the pupa is about twice as large as a mosquito and not unlike a small daddy long legs, with dark wings, shorter than Die very elongated and banded abdomon. The fly shuns the daylight and is seldom seen. In fact it is exceedingly rare in collections."