Insects' Devices.

Star (Christchurch), Volume LXVI, Issue 20477, 1 December 1934, Page 12

Insects' Devices.

Nature Notes.

Bu James Drummond F.L.S., F.Z.S.

COME DEVICES of insects, authenticated by hard-headed observers, are very surprising. It is not necessary to go out of New Zealand to find examples. One of the best illustrations in Sir J. Arthur Thomson’s three-volume work. “ The New Natural Historv,” is a reproduced photograph of a New Zealand stick insect resting inconspicuously against the rough bark of a tree. In the photograph, as in life, the insect, hardly can be distinguished from its support. ’ It looks for all the world like a grey twig. So perfect is the_ protective resemblance that it is almost invisible to h-’man eyes, probably also to birds’ eyes, which are remarkable pieces of mechanism. Tn summer a green mantis may be seen an v where in New Zealand, harmonising with the green foliage amongst which it lives, waiting like Patience on a monument for insects to come and be eaten. Ants’ literature has scores of eXtraordmarv devices ?nd contrivances, all intended to help the different species. Their success may be measured by ants’ presence in all parts of the world exceot the Polar regions, and bv their position as the dominant social Their chief historian, Dr A. Forel. had an interesting experience with members of a European soecies. He saw ants running to a central place on the withered branch of/ an old pear tree. He concentrated his attention on them. Suddenly he saw a very small round hole in the bark. An ant sboped in. and he lost sight of the hole. He could see only the rough brown bark. Another hole was seen. Another ant ran into it and both ant and hole, as in the first case, disapoeared from his view. Having fixed the site, he gently thrust a pin into one hole. On withdrawing the pin, he saw the head of an ant inside, near the opening. It was a soldier ant that acted as -doorkeeper, closing the opening to the dwelling with its head, but standing aside to allow members of the community to enter.