June 1945 School Magazine

June, 1945

"Brisbane Girls' Grammar School Magazine

June, 1945

Brisbane Girls' Grammar School Magazine

KENDALL BROADBENT MEMORIAL PRIZE ESS,?\.Y FOR N.ATURAL HISTORY• . Form V•• 1944. GREEN TREE-ANTS. An insect commonly found in Queensland, the green tree- ant, holds pride of place among the members of our insect world for pugnacity, for industry and for the deve lopment of instinct. These vivid green ants have their habitat particularly in the north of the State and on the cora l islands of the Great ~~~~ . "Hell has no fury like a woman scorned", wrote a poet -of the seventeenth century. He was obviously not acquainted with the green tree-ant. Woe to the unwary one who disturbs them! They swarm forth, attacking all exposed parts of the body, and with a vicious jab bury their jaws up to the hilt- and stay there. This ant will not let go; you can pull its body away, but the jaws will remain embedded in the flesh . In these regions, one often sees amidst the foliage of a tree -a mass of tangled leaves-united at their edges to form a bundle, .sometimes the size of a football. This constitutes the home of some of these amazing insects. On closely examining a nest, found in a mango tr~e, I saw that the leaves were firmly bound togethe r with fine, but strong, threadS of silk. These -ants are themselves unable to produce silk but they obtain it from the larvae, which they use as a weaver uses a shuttle. · I have often maz:.velle d at the nest-building operations of 1hese ants. A whole army will line up ·on the. edge of a leaf and, stretching upwards, seize a h igher leaf in the ir jaws; a ll h eave in perfect union and draw the l"e af down, till it is close io the one on which they are standing. Other workers, hold- ing the young ones with their mouths pointed forward, appear -on the scene of activity. Now, these larvae are ready to secrete a sticky fluid which hardens on exposure to air and is made into a silky cocoon; in this the larva would b e transform- ·ed into an adult. But the instinct of the ant teaches it how v aluable this secretion from the ·young is to the community·. The larvae are passed from one, side to the other, so that the thread formed binds the leaves together.' If the drawing of the leaves together we re confined to those within the re ach of an individual ant, it would only be in 18

the most fortuitous circumstances that leaves close enough together could be secured. I have often noticed the ants form- ing living chains to bring the leaves close together. The ants gather on the surface of the upper one and one of them grips it with its jaws and hangs suspended; a second ant climbs over its body and, clinging to its middle, hangs on; several climb down till the second leaf is reached. Several of these chains may be formed and are often used as b ridges by ants w ishing to cross from one leaf to another. When all is ready .they tug together, exerting a ll their strength, until the two edges a re close enough to be stitched together. Sometimes I have observed a nt-chains contain ing as many as twelve individuals. The g reen tree-ant appears to b e indifferent to the type of foliage it chooses for its nest. If the leaves .are large, fewer are necessary, but the work is heavier; while if they are small hundreds may be require d. The ants, of course, live in colonies and thousands of ants, with the ir eggs a nd young, may shelter in the one· nest. But their labour is not over when the leaves are united exte rn- a lly for wonderful galleries and chambers are constructed in- side, supported by a fmmework of the same silky material. The industry of this a nt is not confined to architecture and constructional work alone, for it crlso runs a-dairy! It tends care- fully flocks of aphids, mealy bugs or scale insects which secrete a fluid. known as honey-dew, as they feed on the .foliage, and it induce s these insects to secrete this delicacy in · abundance by gently stroking their backs with its antennae. This is one of the most a mazing phenomena of Natural History and mdre astonishing still is the fact that the ants fence in their herds. If the aphids show a tendency to wander, the larvae are again used to spin a web about them as they feed. Thus the ants a lways know where the ir charges are to be found. Undeterreciby their pugnacity, the aborigines o f n orthern Queensland relish these ants as food, the larvae b e ing con- sidered a really fes tive dish. Sometimes they <;::ut away the branch and sh ake it to be rid of the ants, leay.ing ilie grubs; or they smoke the ants o4t; or, perhaps, throw the nest in water, when the a dults swim ashore. An acid drink, rather tntoxicat- ing if le ft to ferment,- used to be made among the natives by crushing the ants if! water. · · One chare:cteris tic which these ants possess, in common -!_9·