LEAFLETS FOR FARMERS, NO. 22.

New Zealand Times, Volume LVII, Issue 2549, 29 June 1895, Page 2 (Supplement)

LEAFLETS FOR FARMERS, NO. 22.

New Zealand Department of Agriculture. John D. Ritchie, Secretary. CALIFORNIAN STINKWEED, DIGGERS’ WEED. Navarettia (Gilia) squarrosn. By T, W. Kirk, F.L.S., &0., London. Professor Asa Gray, in “ The Botany of California," VoL 1., p. 493, describes this plant as follows; “ Rigid, rather stout, becoming much-branched, very glandular, viscid, foetid; leaves twice pinnatifid or pinnately parted, and the divisions either parted or incised ; upper leaves and bracts spinescent; corolla blue, rarely whitish, 4 or 5 lines long, rather shorter than the usually-entire calyxlobes." To the ordinary observer this plant, which grows from Gin to 14in in height looks as though bundles of small prickly leaves were stuck at intervals along the stem and branches, each branch being surmounted by a compact spiny-looking ball, with tiny blue flowers standing out a little beyond the circumference. Although not of recent introduction, it seems to have spread with extraordinary rapidity during the last few years in some localities in Otago and Marlborough, and it is sometimes erroneously called “ Bathurst burr." It is also found plentifully in other places. Mr John Moore, Inspector of Stock for Marlborough, informs me that it has reached the head of the Awatere Valley, having been distributed by carriers in the chaff used to feed their horses. This is shown by the somewhat extensive patches growing at their camping-places. Specimens have also been received from Hawke’s Bay; Nelson; Auckland; and from the Wairarapa, in the Wellington Provincial District.

A decidedly objectionable weed, and one which threatens to become a serious evil. No stock will touch it, and if once it gains a hold on land it seems to take entire possession. Moreover, its foul smell and viscid nature are exceedingly obnoxious to travellers. In some parts of the Colony this plant, and also the burr clovers or mediek burrs (Medicago dcnticulata and maculata), are not infrequently called Bathurst burr (Xanthium spinosum); and, as it is very desirable to prevent such confusion, cuts of the true Bathurst burr and cl oyer burr (M. dcnticulata) arc appended fop comparison. A glance at the illustrations will show that it should be impossible for any one to make a mistake in identification.

NO. 28,

New Zealand Department of Agriculture. John D. Eitchie, Secretary. NASAL BOT IN SHEEP: GEUE IN THE HEAD. (OSsirus avis.) By John A. Gilruth, M.E.C.V.S. Sheep, of all descriptions, but especially lambs, may suffer at this time of the year (March) from the presence of the larvae of the CEstrus oris, or sheep gad-fly, in the nasal cavities and'sinuses of the head. From the margin of the nostrils, where the fly deposits them (or the eggs) the young larva? make their way through the nasal passages into the sinuses or aircavities of the head, where they may often be seen on splitting open a sheep’s head in winter. During the winter and spring they mature, after which they become detached, and are expelled on to the ground, where, in about forty-eight hours if circumstances are suitable, the larva? becomes a chrysalis or pupa. They remain in this state for a period of from six to eight weeks, when, development having taken place, one end of the pupa j

case breaks off, and the complete fly or imago escapes and seeks its mate. The (Estrui may bo found during the summer months on walls and fences in the neighbourhood of sheep, especially near plantations and bush. “Itis a dullcoloured insect, with head and thorax together about as long as the five-ringed abdomen; its back is brown, with small points and patches of a darker tint; its under-surface dark-brown, with a spot at the centre of each abdominal segment. The wings are two in number, almost as long as the entire body, and nearly completely enveloping it, variegated with spots and stripes, and having small horny internal portions which envelope the poisers or balancers; small _ chitmous organs representing the posterior pair of wings of all Dlplcra. . . . The head is large, yellow and spongy in appearance.'I—Stech, 1 — Stech,

In older countries, during the attack of the fly, sheep become very excited, even though only one fly be in their vicinity. They stamp with their feet, snort, shako the head, rush about and hold the nose to the ground, burying it amongst any soft soil or dust that may be near; at other times the sheep may be found packed together, stamping and snorting fiercely. Flocks, however, in New Zealand become affected with the larvae without any previous agitation of the animals having been noticed. Both old and young sheep may be affected, but lambs as a rule experience more inconvenience. It is when these parasites are in the earliest and in the later stages of their larval existence that most is experienced by their hosts —that is, during the passage to and from the sinuses of the head. The young larva;, which are whitish in appearance, progress partly by means of two anterior hooks, but chiefly by means of an independent worm-like movement; and, though their chief abode

is in tho frontal sinuses, they may remain for a considerable time in the nasal passages and convolutions of the turbinated bones. It has been asserted that they ■ often penetrate to tho brain, but this is extremely doubtful, considering that in order to do this absorption of the bone would have to. take place. Such assertions have arisen because on opening the cranial cavity by means of a hatchet or saw the Jarvgi have been found about tho brain substance, having bee'n carried through during tho splitting operation. The amount of irritation due to the presence of these parasites naturally depends, to a certain extent, on the number present, which is generally stated as being from one to eight; but I have found as many as thirty-five in the nasal passages of one lamb. When the irritation is considerable it may produce indoughs membrane. The symptoms are chiefly a choking cough, frequent sneezing and snorting, shaking of the head from side to side, rubbing the nose on the ground, Sec., swelling of the nostrils and discharge of watery mucus. At times there is depression and disinclination to feed, accompanied by securing, • There may be sudden convulsive movements of the head, with the nose carried high in the air; and from time to time the animals stagger and may be attacked with vertigo. The eyes may be red, with a discharge of tears. Sometimes convulsions set in, when death ensues in a few days. In spring, again, when larva) are passing down the nasal passages, loss of condition, discharge of bloody mucus from the nose, &0,, may result. When animals are exhibiting the above ■symptoms it is highly necessary that some treatment should be resorted to. The inhalation of tobacco smoke and of the fumes of burning sulphur are said to be beneficial; but my experience as to these remedies is that they are far from being efficient. These larva are difficult to kill, for they have great powers of resistence. If the lorvte are still in the nostrils—-

which shoulj bo determined by killing and c.\amiai n „ ail affected animal—the sorest mothsd is to syringe the nostrils witli soma a u ;Q w l l i c l lj jf ; t j oeg nol coln . pletoly MU lfi a parasite, will cause it to lose hold and bo expelled. For this purpose I have lomjd the following mixture to be of benefit; Carbolic acid, 1 part; oil of turpentine, 8 parts; glycerine, ill) parts; and w»i er t 0 make 60 parts. The operation should bo performed by means of a small vulcanite syringe holding about two drachms - rhis ig ° fil]e(l J th t " mixture, and half of the quantity injected g i £ V Vn h The animal nostrils the annad shou f d allowed lo sneeze fioely. I n caSO3 wbero d i ßturb . nuce is caused by the presence of law® in the sinuses of the head the only remedy i a surgwal operat.on, which it i 3 not desir able that any one but a qualified veterinanan should perform. In tins, as m all other parasitic diseases, however prevenuop is the best measure to adopt, I his can be accomplished partly by destroying all larv® found on openiuanimals, ami partly by taking precautions to pieient the fly depositing oggs on the sheep. For this purpose furrows in the pasture are useful, so that the sheep may bury his nose amongst the soft earth dormg the attack of the fly; sprinkling the sheep s salt oyer tar; and application of fish-oil, tar. Are., over the region of the nostrils, which is best accomplished automatically by placing the salt in a long box covered by a lid perforated with round holes about two inches in diameter, the margins and upper surface of which should bo smeared with the substance to bo used : thus every time the fshoep lick the salt they will receive a -dressing. By such means ns these the fly may be prevented from depositing eggs. *' Wellington, March, 1895.