LOUSE INFESTING THE LEGS OF SHEEP.

New Zealand Journal of Agriculture, Volume XIX, Issue 1, 21 July 1919, Page 15

LOUSE INFESTING THE LEGS OF SHEEP.

FURTHER OCCURRENCE IN NEW ZEALAND.

C. S. M. HOPKIRK,

Veterinary Laboratory, Wallaceville.

In 1911 some sheep in the Banks Peninsula district were found to be harbouring a louse which was quite different from any noticed previously in this country. Inquiries resulted in specimens being submitted to a British authority on the subject of lice, Mr. F. W. Garnett, M.R.C.V.S., who pronounced them to be a new species, which he named Ha,ematopinus microc&phalus. Later, specimens were submitted to Professor L. G. Neumann, of Toulouse, who claimed that this louse was identical with others in his possession found on sheep in Argentina in 1896, and described as H. pedalis by Osborn in a bulletin of the United States Department of Agriculture (No. 5, New Series, Division of Entomology, p. 170). Mr. H. A. Reid, F.R.C.V.S., D.V.H., has already given an illustrated account of the parasite in this Journal (December, 1911), but using the name H. microcephalus as classified by Garnett.

Since 1911 this louse has been noticed only once or twice on sheep in New Zealand, or else specimens have not been submitted in every case to this Laboratory for identification. The last case to come under notice was in May this year from the Wairarapa, where one sheep was found to be badly affected. The owner of the affected sheep in the South Island had bought sheep from Hawke's Bay a year or two previously, so that, judging by the two cases, it would seem that the louse made its first appearance in New Zealand around the latter district. Whether this view is correct or not would be rather difficult to determine at this late date.

On the sheep sent in to the Laboratory on this last occasion H. pedalis was found to be present in great numbers on all four legs, from the coronet to wherever the hair of the leg gave place to the wool. Only the legs were affected.* Wool is apparently too greasy to harbour it, as specimens were found in the belly wool in a starving condition and not attempting to feed. Eggs were present in* very large numbers

adhering to the first locks of wool above the hock of the hind legs, and it was no doubt this brown mass which first drew the attention of the crutcher to the lice on the sheep. In appearance and size the parasite is very similar to the ordinary dog-louse (H. piliferus), with which many dog-owners are familiar. ‘. The condition of the sheep is apparently not affected to any great extent, and, although the louse. obtains its food by sucking the blood of its host, there appears to be very little irritation'. Occasionally the affected sheep is seen to bite at the leg when' lying down. A sheep placed in contact with' the lousy animal was found to have become in its. own turn affected, proving that precautions must be taken to safeguard the flock.

As regards treatment, the louse is easily killed, and does not live beyond a week away from the body of its host under ordinary conditions. Dipping is effectual, as with other species of lice, and sheepowners should therefore have no difficulty in dealing with the vermin whenever they make their appearance in the flock. Specimens will at all times be welcomed by the Officer in Charge of the Veterinary Laboratory, WaUaceville, to enable it to be ascertained if possible how the louse gained access to the Dominion, and in which parts of the country it is at present situated, and to what extent it is now present in our flocks.

DIRECTIONS FOR MAKING TARPAULINS.

The material for a tarpaulin should be hemp canvas or cotton duck, not lighter than 16 oz. The sheet should have the seams doublestitched, and not less than eight stitches to the inch ; the eyelet-holes for tie-ropes to be brass eyelets or galvanized-iron rings sewn in. Pure boiled linseed-oil, with a little paste dryers added, will make a thoroughly waterproof sheet. If black dressing is required add vegetable black to the oil and dryers ; if yellow, add yellow ochre ; and if brown, add Indian red and a little vegetable black. If time is no object in drying add a little fish-oil, and this will make the tarpaulin very soft and pliable and increase its durability. In order to produce a satisfactory tarpaulin it is absolutely necessary that the dressing should be carefully applied. The sheet to be dressed should be thoroughly stretched on an even floor while being treated. For the purpose of applying the dressing a rather stiff brush is required. The dressing must be well worked into the canvas, especially at the seams, and equally distributed over the sheet, so that none of it remains on the 'surface in patches. When one side has been coated the sheet must be hung up and allowed to remain suspended till thoroughly dry. It will then be ready for coating on the other side, and when this has been done hang up as before. When the sheet is again taken down the first side coated must get another coating, and this should be sufficient to make it thoroughly waterproof. When the sheet is drying it should be exposed to free currents of air ; dry air is specially desirable, but the sun's direct rays must be carefully excluded. The sheet thus finished should be allowed to hang z till thoroughly seasoned. Public Works Department. ' .

* Another rare species of louse, H. ovillus (also referred to in the December, 1911, Journal'), is found only on the face of sheep, and therefore it is possible to distinguish one from H. -pedalis by habitat alone without recourse to the microscope.