WAYS OF THE WILD.

Auckland Star, Volume LXI, Issue 241, 11 October 1930, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK, N.Z. TERMITES, OR WHITE ANTS.

(By A. T. PYCROFT.)

Mr. H. Fleming', of ScaeliiTe Road, Takapuna. has sent me for identification some insect larvae. They are the larvae of one of the three species of New Zealand termites. Mr. Fleming states that he obtained them from a dead macrocarpa stump and wishes tn know what damage they are likely to qjiuse and if they are the Australian white ant. Mr. Fleming has also found them in poplar and puriri. Specimens in macrocarpa have also been received from Sir. Gilbert Wilson, Long Drive, St. Helier's, and infested puriri has also been received from Mr. W. Rutherford, who obtained the puriri from his lat;> property at Bombay. All three species of New Zealand', termites, or white ants as they are popularly called, although they are not ants, attack timbers and at times cause considerable damage. A well known Auckland architect infjnns me that in his opinion the ravages of white ants are far more destructive to buildings in Auckland than are the ravages of the common house borer (anobium doinesticum), although the latter i? more plentiful. Dr. D. Miller, Director of the Cawthron Institute, states that the damage caused at times is so considerable as to give rise to the idea. thkt one of the Australian white ants has become established in the Dominion, but the species responsible for any d-image are native ones. The importation of Australian species 011 hardwood poles is, of course, a constant danger. A considerable variety of timbers is attacked, including puriri, and it is possible that infested puriri timber used as house blocks has later caused the general infestation of the house timbers. Totara, kauri, rimu, matai and eucalyptus, besides poplar and macrocarpa mentioned by Mr. Fleming, are also subject to attack, and whereas the house borer's ravages are not so prevalent in heart timber the white ants do not discriminate between sap and heart.

What Termites Are. Termites is the plural of termes. Latin, a wood worm. Termites belong to an order of insects, tlie iioptera, which have two equal pairs of large membraneous net-veined .wings. Insects of this order are of an archaic and ancestral type with many fossil representatives. Each of our three species is social after the manner of, true ants, which belong to another order, the hyinenoptera. Termites make nests, either in wood, or else they make them on top or underneath. The New Zealand forms do not make large nests like tropical species, whose nests are sometimes twelve feet high, but are found in the wood from which they make their nests. The damage done to timber is very characteristic; they completely hollow out the object they attack and always work with the grain; for that reason they are often overlooked, only the shell of the timber being left. In Australia termites attack books, leather, household utensils and food. They feed mainly on cellulose, the substance which constitutes the essential part of the solid framework of plants, of ordinary wood, linen, paper, etc. Termite? are divided into a number of castes. First, the workers, which are most numerous and have very undeveloped sexual organs. They are blind and wingless and their work is to gather and digestfoodstuffs. In many cases the «:orkers are the only ones who are capable ,of digesting cellulose; they therefore feed the other castes. - In forms which make large mounds, such as the termites of Northern Australia, the workers do all the construction and all the damage. Workers are sometimes divided into two groups according to size, the largo are active, the smaller look after the eggs and larvae. The next caste are the soldiers, which are sexless and blind, the eyes being quite absent, but are possessed of huge mandibles, used for fighting. They are incapable of eating. Soldiers defend the workers and in tropical forms, if a breach is made in the mound the soldiers push their heads through and thus defend the breach. Some, soldiers can eject a sticky liquid which is a good weapon of defence. The hereditary enemies of white ants are Ants themselves; there is, therefore, un-

ceasing war. . . 1 The king and queen are the original male and female whose progeny form the colony. The queen is solely engaged in egg laying, and her abdomen is enormously swollen. Unlike bees, fertilisation of the queen is frequent, and does not take place until after the original flight; also unlike bees there not alwavs Just one queen. When egglaying falls below a certain mark another male and female may be introduced into the same nest or eoJony, tue original king and queen being k lied. The royal pair are fed by the worker*. The king, before pairing, casts his \vings, and remains very mucli like an ordinary individual. Nymphs are another caste, their larvae forms being otten lound jn the nest. Thev are larvae of winged males and females. These insects swarm at times. Another caste, the neotennjc, I are substitute forms. They can be distinguished by having wing sheaths and are° reared from specially selected nymphs, and are kept so that if either of the royal pair dies they can be replaced, or else the colony can be split up and sub-families formed. There are also undifferentiated larvae, which after further development, will attain to one of the recognised forms.

Method of Eating. The termites which, feed exclusively on cellulose are unable to digest it, go the problem Is solved in two ways, First by a large number of protozoa—from protos, first and zoon, an animal —found in the "termites' intestines. These protozoa are able to digest cellulose, and. having done so die, and are then digested v the termites. If termites are subjected to a temperature of over ninetysix degrees Fahrenheit the protozoa are killed, and although the termites do not suffer greatly they cannot now digest cellulose and starve. At certain times of the year winged members are impelled to migrate. They leave the nest in enormous numbers, and seldom rise high, their flight being decidedly wobbly. During and after flight they are preyed on by birds. The body .of thb winged insect is shining reddish brown. Usually only a 6mall number of eggs are laid at the start oi a colony, and most of the larvae of the first brood develop into workers and a few_ wto soldiers. The royal couple feed the young. Egg laying is not continued until the first batch of young is after that egg laying occ ° r ® I £2e to intervals Then the royal pair cease to feed and depend entirely on the worker,. To New Zealand species » great number in j.«w , . jajd a t one time, beU™ i°> rd voods > and wSrs conH not'-burrow enough.