Forest insects and timber borers

Front matter

Press

F927 eee Ento.

il useum Victoria

Contents

Introduction ...

Forest Zoology

The Forest Guard ie Black Games Forest Entomology ..

Introduction

Tue following pages, most of which have appeared in The Australian Forestry Journal, illustrate the work upon which I have been engaged during the last three years while special forest entomologist to the Commission. Soon after my retirement from the position of Government Entomologist to the Department of Agriculture, an unofficial committee was formed by the various associations interested in the timber and building trades, to which I was invited to attend. We had a number of meetings to consider the increase of timber pests and the best methods to be adopted to check their ravages, and to prevent the importation of foreign species. As an outcome of the deliberations of this committee, the then Minister of Lands and Forests (Hon. W. E. Wearne), who himself took a keen interest in these matters, received a deputation, at which most of the associations were represented.

At this meeting he promised to have investigations carried out, and shortly afterwards the Cabinet, at his request, appointed me for the term of a year as special forest entomologist to carry out investigations dealing with these matters. This appointment was renewed for another year, and was in force when Mr. Wearne retired from office. When it elapsed the Hon. P. F. Loughlin, who also took a keen personal interest in the timber and forests of Australia, had it again renewed till the end of last year. At the united request of Mr. N. W. Jolly, Commissioner of Forests, and the Hon. W. F. Dunn, Acting Minister of Lands and Forests, the Premier, the Hon. John Lang, agreed to my appointment being extended to the 31st March, 1927.

During my tenure of office I have visited many town and country sawmills, and examined large numbers of logs and shipments. of sawn. timber, chiefly from the East and the Pacific Islands. I have travelled through many of our large forest reserves, and have collected and examined all kinds of timber and other forest insects. Large numbers of borers have been cut out of felled trees and seasoning timber, many collected in the earlier stages of their development and their habits studied in the [Forestry Insectarium; all have been examined, identified, classified, and placed in the cabinets.

All specimens doubtfully named or unknown to me have been submitted to the leading authorities on timber insects. Mr. Paul Lesne, of Paris, has identified the Bostrychide and Lyctide; Lieut.-Colonel F. Winn Sampson, of London, has examined the Scolytid@. Others have been named by Mr. A. M. Lea, of Adelaide. During the last three years I have had an intensely interesting time, and have met with unfailing courtesy from the members of the timber trade and from all the officers, both in the field and office staff, of the Forestry Commission. It is through the great assistance given me by them that I have been able to gather together in so short a space of time much of the information included in this Bulletin. I would particularly like to mention the practical assistance given by my friend Mr. W. L. Wearne, who has interested himself for some years in the most up-to-date methods of destroying borers in timber; he has not only placed his practical knowledge at my disposal, but has roused an interest among the saw-millers and timber merchants in the value of protective measures. I would also.thank Mr. C. F. Davies, of the Brooklana Timber Company, for the assistance given in carrying out our experiments in the Dorrigo forest on the treatment of timber to protect the timber against Powder-post Lyctus beetle infestation while seasoning at the saw-mills. ee

My first-hand experience of treating timber enables me to state that at a very reasonable cost all our valuable forest timbers can, after they have been cut up on the saw bench, be protected during the period of seasoning from Powder-post beetles, after which they are immune from infestation. These beetles strictly

2, confine their attention to the sapwood of the timber, but in many of the logs there is so much sapwood that it would not pay the saw-millers to mill the log and cut out the outer portion. In most trees this outer portion of the log comprises sound timber as useful and enduring as the harder heart wood, which is only rejected at the present time because of its liability to be infested before being made up into furniture or buildings by the larve of these beetles.

There are many thousands of pounds worth of fine timber annually destroyed by another very distinct family of small timber borers. These are logs which when delayed in transit from the forests to the saw-mills remain where they have been felled or assembled on the river bank for shipment, and become infested with tiny ‘“pin-hole” borers. These beetles and their larvae remain feeding and multiplying, and cut their way right through the heart wood, working in the log as long as it contains any moisture. This infestation takes place in our coastal forests, but is most serious in the forests of the Pacific Islands and the East, timber companies frequently sending shipments of logs to Sydney saw-millets which, when cut up, consist of nothing but “ pin-holed ” second-rate timber, for which they have to take anything they are offered.

Considering the value of these logs when delivered in a sound condition at the saw-mill, it would certainly pay the owners to spray or paint these logs as soon as they are felled in the forest, barked or unbarked, with an adhesive repellant mixture of creosote, tar, and oil, which will keep all pin-hole borers away. Some of the up-to-date merchants both here and in Borneo and the Philippines are using these protective methods with marked results.

The study of forest entomology includes many interesting and important problems before the trees become commercial timber. With the replanting of forests all over the world, and the regeneration of our forests, we are sure to have an increase of forest pests. While we have many indigenous insects peculiar to our forest trees, we are also always in danger of introducing foreign pests, which, free from the natural parasites which keep them in bounds in their native land, are nearly always more destructive than indigenous insects.

Among our own recognised pests may be mentioned the various species of Bag or Case moths, stripping all the foliage off trees in avenues and plantations ; the Cedar tip moth, which has virtually stopped the development of cedar plantation both here and in Queensland; the Lace Lerp, which defoliates the ironbark saplings over a large area of our northern forests; and moth and beetle larve which remain for several years developing from grub to perfect moth or beetle in the roots or trunks of growing trees.

I think that the series of articles included in this Bulletin will convince anyone of the necessity of having a forest entomologist (who can devote the whole of his time to the work) attached to every Forestry Department in the Australian Commonwealth.

There should be plenty of young men in Australia who, with a little training, could take up this important and interesting work. One with a general knowledge of the conditions under which our forest trees grow, and also of the type of men working in the forests with whom he comes in contact, would have a great advantage over the theoretical student fresh from college. A working knowledge of the botanical and popular names of the forest trees and shrubs would help him very much in his study of forest entomology. Also he should be a man not afraid of roughing it when doing field work in the forest, for a forest entomologist does much of his collecting with an axe, not a butterfly net.

ORES iieZ@ @lEOGNE

A WELL-KNOWN writer has said, “If it had not been for man, the whole world would be ruled to-day by the forest.”

Richard Jeffries, the nature-study writer of England, in his remarkable book, “After London, or Wild England,” tries to visualise what would happen if London and the civilization of to-day vanished. He graphically outlines how the whole of England rapidly reverted to the dense forests and thickets of prehistoric times.

In modern times it is hard to realise that two thousand years ago the whole of Great Britain and Europe was one unbroken forest, stretching across from the Baltic to the Mediterranean Sea. In its shelter the ancestors of the present nations of Europe dwelt, and hunted for their food, developing through the ages to the present standard of civilization.

The forest not only tinged all the life, but even the religion of the different tribes. In the dense sombre pine forests of the north, where life was one long struggle with the elements, the inhabitants peopled them with stern all-powerful gods—Thor, Odin, Woden. In Southern Europe the open glades of the oak and elm forests of Greece and Italy were given over to wood nymphs, fairies, and dryads. Both the stern old gods of the north and the merry goddesses and gods of the south have vanished for ever. In Australia, few of our most imaginative forest dwellers found time for more than a description of an echo down a gorge. There is hardly a record of any bird or animal which sheltered in our virgin forests when the cedar-getters opened up the Northern Rivers.

No one thought of saving even a few acres on any of the river bends, for a forest park, or for a national reserve. Perhaps the most notable exception is the patch of virgin bush on the Manning River at Wingham, due to the exertions of the late W. Allan. It remains a nature monument to his memory. Our Australian forests are full of wonderful creatures. Of these only the nature-lover and the naturalist know the infinite number and variety. They find food and shelter within and upon our forest trees. Whenever a tree is cut down and destroyed innumerable little creatures are homeless. When whole forest areas are cleared and burnt down, without even a single shade tree left in the paddock, a world of little lives is banished. The birds fly away, and the forest animals are killed.

A very large number of Australian animals are nocturnal in their habits. Opossums, sugar squirrels, bandicoots, wombats, native bears, and the smaller rodents hide in the wood and feed at night. Even the larger kangaroos do much of their grazing in the cool of the evening.

Having realised this, one can understand what an important part forest cover plays in the protection of our indigenous animal life. Every hollow limb of a tree, every cavity in the trunk, has a resident lodger.

It is inevitable that, as civilization advances, forests must be cut down and cleared away to make homes and profitable holdings on which to grow food. It is usually the richest land which grows the densest forests; but there is also’ much forest land which is neither suitable for growing crops, or even for grass when ringbarked. |

It is want of knowledge of these conditions that has led to the clearing of mountain ranges, and of plateaux which, like the whole of the Dorrigo Plateau, should have been strictly defined as national forests for all time.

Before there was a Forestry Department the Lands Department had a free hand to deal with public lands. When Forestry Commissions were created in the different States, much initial damage had been done, and much poor land alienated. Until recent years there has been a tug-of-war between the two Departments, Forestry asking for the dedication of forest areas for the State; the land-seekers constantly urging the resumption of such land for settlement; and it certainly did not add to the popularity of the Lands Department to refuse the applications.

All credit is due to the officers of the Lands Department for the large number of reserves and sanctuaries for flora and fauna which nave been withdrawn from sale or selection. In a list furnished to me by the Lands Department there are 105 reserves. in New South Wales for the preservation of native flora alone.

These reserves vary from 3,000 to 16,000 acres in extent. A list of many large areas, which covers over two pages of the Government Gazette, issued 7th January, 1927, defines the districts as sanctuaries, where no shooting is allowed, and where animals and birds are protected all the year round. All State forests covering another large area are proclaimed sanctuaries, and the forest officers have authority to deal with trespassers. So that we now have some hope of preserving both our flora and fauna under the present enlightened administration.

In considering the animal life of our forests we must go back to very early days, when kangaroos grazed over the flats of Petersham, and were hunted at Long Nose Point, when they incautiously entered that narrow neck of land in a suburb of Sydney.

When domestic animals and foreign plants came into competition with our indigenous fauna and flora, pests of both animals and plants developed from introduced species of both. Prior to the advent of man, our animals and plants had grown up together in the forest, side by side, throughout the ages; they adapted their lives to each other, and developed resistant qualities to the varied climatic conditions of Australia. ~ When, however, by the alteration of the balance of power, usually the removal of some natural check, there was an abnormal increase of any particular species of plant or animal, something suffered. Some animals’ food plants were in danger of extinction; on the other hand the plants overgrew themselves, became thickets of stunted ‘saplings which, attacked by insect and fungus pests, died when drought conditions prevailed. But where man or his foreign plants and animals did not intrude, nature always reasserted herself, and normal conditions returned.

We have three dominant plant pests that have made serious inroads to our forest lands. First and foremost, the prickly-pear (Opuntia) ; second, the lantana ; thirdly, the blackberry, with its trailing thorny canes.

We have in Australia a remarkable uniformity in our great Jand areas. Over the greater part of the continent, the dominant forest flora consists of trees belonging to the two great botanical genera, Eucalyptus and Acacia, popularly known as “ Gum tree” and “Wattle.” Botanists have classified over 200 species of eucalypts, and over 500 species of acacia, scattered over the whole of Australia.

At the same time we can roughly divide our forests into three distinct types, though in places they overlap each to a certain extent. Within these types are to be found birds and animals peculiar to each.

The first division, and most important from a commercial standpoint, is the hardwoods forests. These almost encircle Australia, and extend inland for a considerable distance in many parts of the continent. These myrtaceous trees, which vary in form from the stunted mallee scrub gums of the interior to the giant blackbutt of the Gippsland forests of Victoria, comprise the commercial hardwoods. They are known under many popular names; the jarrah and the karri of South-west Australia, messmate, tallow-wood, spotted gum, red gum, ironbark, blackbutt of the eastern coast, blue gum of Tasmania and Victoria.

This type may be described as forest, with or without undergrowth, and sometimes with little undergrowth, often containing park-like lands, lightly clothed with grass and small shrubs, the home of kangaroos and other grass-feeding animals. The second type of forest, though limited in extent in New South Wales, spreads out into more tropical coastal valleys and mountain ranges of Queensland. These forests are known as “cedar brushes,’ because red cedar was the chief timber cut out by the pioneer timber-getters. They have also been called “rain forests” in Australia and the Malayan Islands. Besides cedar, most of which was cut out forty years ago, they contain many fine timber trees, among them Queensland maple, crab apple, red beech, sassafras, silky oak, suitable for furniture and interior decoration. Allied to these are the “plateau forests”; such is the Dorrigo scrub which is the natural home of the hoop pine, and is interspersed with the forest trees previously enumerated. é

The third type is the “western scrub forests,” west of the coastal ranges. It may be said to spread over the dry wilderness lands of Central Australia. The great “Pilliga Scrub” comprises about 3,000,000 acres of open forests; cypress pine, casuarina, ironbark, and a host of small scrub trees. It is a fine example of the dry land forest, of which the cypress pines are the most numerous and the most valuable timber trees.

As eucalyptus and acacia are the dominant trees in our forest flora, kangaroos, wallabies, opossums, and _ native bears take. first place in the forest fauna. These, particularly kangaroos, have played an important part through the ages, in the growth and development of the forest. They should be encouraged now to play a more important part in protecting our young forests.

The greatest enemy of forests, the nightmare of forest officers all over the world, is .

fire. Thus, one of the chief difficulties in reafforestation is to keep down the grass without injury to the smaller trees. If grazing permits are allowed, and sheep, horses, and cattle are depastured in any forest, the seeding and young trees suffer. In some of the large red gum forests on the Murray River, where sheep are constantly grazing, there is hardly a seedling or young trees to acres. They bite off the tops of the young trees, and in a bad year they eat them down to the ground.

Cattle are nearly as bad. They not only eat down all the soft foliage trees, but break down the young saplings; they are exterminating some of the rare trees. In many of the western scrubs, the beautiful, graceful quandong (Fusanus acuminatus), with its silvery foliage and bright red_ fruits, was quite a common shrub on the sandhills before cattle were turned out. Cattle are particularly fond of it, breaking it down and eating foliage and branchlets. Last season, when dry conditions reigned for months over the Northern Rivers, horses and cattle ate down all the young red cedar trees grow-.

ing on the edge of the forest. To comprehend how the grazing of sheep will affect our western scrub lands, one need only fence in a small area round his homestead or horse paddock, and watch how rapidly it is clothed with young seedlings of the boree or Weeping myall (Acacia pendula), and other characteristic plants non existent outside the fence in the sheep run.

The Kangaroo.

The kangaroo is the natural guardian of the forest. He is not a herbiferous animal. The structure of the teeth of the kangaroo is remarkable. The two front teeth, loose and shaped like scissors blades, show how they are real grass-cutters; so that he cannot to any great extent feed, if he wanted to, upon the foliage of trees. ;

Now, all our State forests are sanctuaries. With very little extra protection the various species of kangaroos and other small marsupials would soon breed in sufficient numbers to eat down all the rank grass in the forest lands.

The danger from fire would be greatly reduced, without any damage to the growth of the forest. When the kangaroos had outgrown their food supplies on the living areas, it would be a very simple matter for the forest rangers to have a round-up, and kill off the surplus animals. At the present price of kangaroo skins the utilization of the open forest as kangaroo ranges would be a very profitable investment. While improving the forest areas they would bring in more money to the Commission than the sale of grazing permits to the adjoining land-owner.

The Opossum.

Under normal conditions, opossums are found in all our hardwood forests. It is only a matter of: adequate protection from illegal shooting, that would rapidly increase their numbers. Under favourable conditions opossums breed very quickly. With the wholesale destruction of iguanas or monitor lizards, on account of their fondness for poisoned rabbits, combined with the extermination of hawks and’ eagles, through settlement, all serious enemies of the opossum, they are living now under improved conditions.

They feed almost exclusively upon the foliage of different species of eucalypts; and we have large areas in which the opossum could be profitably farmed and protected, there is no difficulty in breeding opossums. When taken to New Zealand some years ago and liberated in the forests, they multiplied so rapidly that the trees were defoliated before the damage was traced to the opossums. Their protection was removed, and the surplus caught and skinned. More recently, numbers were turned out in the great nature reservation at Wilson’s Promontory in South Victoria. Here enemies were also non-existent. Since then they have increased in such numbers as to strip large areas of foliage.

During the last twenty-six years millions of opossum skins have been exported to Europe and America, and their market value is rising every year. There should be a steady revenue from protected opossums, even if special officers had to be appointed to police the forest areas.

The Native Bear.

There was a time when the native bear, one of the most helpless and harmless animals in Australia, was common all over the big gum forests, from Gippsland, Victoria, to South Queensland. About twentyfive years ago some obscure disease spread along our coast; and native bears died in hundreds and fell from the trees. The ringbarking of large areas of the forest also destroyed their supplies (gumleaves), and they wandered into adjacent gardens and orchards. Here they were killed in scores. Later considerable numbers were found in South Queensland. People leased Crown land areas simply to get the right to shoot native bears for their tough, thick skins, and short fur, which was sought after in the American fur market.

There is no reason why the native bear should not be able to hold its own, and to increase in numbers, if properly protected in suitable gum forests.

The Wombat.

I have some diffidence in introducing the wombat to the favourable notice of the forestry officers. A harmless hard-working Australian, he digs deep burrows into the hard soil, looks after his wife and family, and usually lives in rough, rugged country. He has one vice, which causes him to be treated as an outlaw with a lawful bonus on his head, though his skin is of little marketable value. He is a thickset bull-headed creature who sternly objects to wire-netting. His habits are nocturnal; and living underground he is not often seen by the ordinary traveller. When in his nocturnal rambles he comes up against a wirenetted boundary fence of a forest plantation, he does not go round, but sets to work and, with his powerful jaws and stout legs, tears a hole through it and continues his ramble. The holes are soon discovered by the rabbits and hares, and a great deal of damage to the young trees may be done before the forest officer locates and mends the

ole.

Flying Squirrels.

There are many flying squirrels and sugar squirrels hidden in the hollow spouts on the dead limbs of the forest trees, but they are seldom seen unless one is camping at night in the forest. Many small rodents, rats and mice, roam through the bush at night, sleeping through the day under the roots of the trees or coiled up under hollow logs. That quaintest of Australian animals, the anteater, is busy through the night digging into ants’ nest for his supper, his curious grunt when alarmed, one of the most distinctive voices of the night.

The Rabbit.

European rabbits were included in the list of live-stock which arrived in the colony of New South Wales with the first fleet, and there were many subsequent importations. They were even turned out in 1851 on the Upper Murray. None of those early immigrants appear to have gained a footing in Australia. It was from other importations into South Australia and South-west Victoria that the rabbits bred up. In the early eighties they started their exodus northward, crossed the Murray, and spread all over New South Wales.

Besides being a very serious pest to the pastoralists and farmers, they do a considerable amount of harm to forest areas. They eat the young seedlings and small shrubs when grass is scarce, and gnaw the bark off trees. In the mallee scrub country of North-west Victoria in the early eighties they were most effective ringbarkers. Standing on their hind legs they stripped the bark of thousands of mallee gums as far as they could reach up the stems. The presence of rabbits in the vicinity of any forest plantation necessitates enclosing the area with wire-netting.

The Hare.

Though never very numerous, and usually living more in agricultural areas, the hare, another introduced animal, often takes up its residence on the edge of the forest. If they find their way into a forest plantation they have the bad habit of nipping off the tops of the young trees, and nibbling off the bark, which they seem to take as a tonic. In this manner a solitary hare often does a great deal of damage

' before it is discovered.

Birds.

The birds of the forest have been dealt with in my previous book, “The Forest Insects of Australia,” but all students of forestry know the important part that many of them play in distributing the seeds of the trees through the forest. Others deal with wood borers and defoliating insects.

In traversing the forest where timber-getters are cutting the marketable trees one naturally finds a large increase of timber-boring insects, on account of the amount of dead and decaying wood strewn over the floor of the forest. .

Some insects attack the logs as soon as they are cut up in the forest, and also dead logs abandoned because of faults or internal damage, which renders them valueless for the sawmiller.

The heads and stumps of the felled trees soon become riddled with grubs or larve of all kinds of insects. Some confine their attention to the bark. Many feed between the bark and the sapwood, and others continue working their way right through the heartwood as long as there is any moisture left in the log. In tropical forests the most important problem for the timber company, particularly if exporting the timber in the log, is to protect these logs fromthe swarms of tiny pin-hole borers (Xyleborus). This borer is always on the move in these forests. Thousands of pounds are lost annually through such logs being “pin-holed” before they reach the sawmill. The only way of overcoming the difficulty is by coating such logs; by spraying or painting them with some. repellent adhesive mixture as soon as possible after they are felled and cut up in the forest.

The increase of insects in the forest areas will mean more food supplies for our native birds, so that the value of making every forest a sanctuary where the birds are not molested is a wise move on the part of the Forestry Commission.

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THE FOREST GUARDIAN.

THE BLACK COCKATOO. (Calyptorhynchus funereus, Shaw.)

Tue Australian forests with their varied flora give food and shelter to some of our most beautiful birds, from the tiny honey eaters, to the great wedge-tailed eagle.

As is always the case, these birds are adapted in structure for the life they lead. Most of our eucalypts, banksias, and such smaller shrubs are rich in nectar; and those birds which live on the honey of the flowers, have the slender beak and the delicate feather-tipped tongue so well illustrated in the dainty little “cobbler’s awl.” This bird is not an uncommon visitant to our suburban gardens. The ground-feeders, such as the brush turkey, have powerful scratching feet and a solid bill for destroying hardbacked beetles, and for smashing the shells of the land shells.

Among the most characteristic which cannot live away from the forest lands, is the black cockatoo, with its dark somber plumage, and its harsh whining screech. At one time this bird was very plentiful, and was widely distributed throughout our big tree forest along the eastera coast, and even extending far inland in suitable areas. The writer remembers a large flock in the sandstone gorges at the head of the Flinders River, Central Queensland. It came to feast on the flowers and the hard seed capsules of a yellow flowering eucalypt. In the early days of settlement, a writer describes how he disturbed a large flock on a drive from Sydney along the Old South Head road.

Broadly speaking, they are never very numerous, and do not congregate in large flocks, as do the sulphur-crested white cockatoos and galahs.

Black cockatoos are peculiar to Australia, New Guinea, and the Malay region. There are five species described from Australia. Three of these are found in New South Wales.

The Yellow-eared Black Cockatoo (Calyptorrhynchus funerius, Shaw) is the commonest species, ranging from Tasmania to Queensland. Its feeding habits may be considered omniverous. It eats seeds, cutting up seed cones such as the calyx of the flowering gums. It cuts out and devours the many wood-boring larve of beetles and moths, which otherwise would do so much damage in our forests. In our hardwood (eucalyptus) forests, in the cedar brushes, and in the open wattle scrubs, there is a remarkable beetle and moth fauna. The larve of these beetles and moths feed in burrows they make on the living trees; and their infestations are responsible for the stunted growth or the death of hundreds of otherwise healthy trees.

When once the larve of these forest insects emerge from their eggs deposited on the bark, their object in life is to cut their way through the bark, and to gain the shelter of the sapwood. A very large percentage never get through the bark. Others are hunted and devoured by predaceous insect larve while feeding in the sapwood. Those, however, who escape all these dangers, and get securely entrenched in their chambers in the heart of the tree are secure from such dangers.