Leaflets. Nos. 101 to 200 / Board of Agriculture and Fisheries.

  • Great Britain. Board of Agriculture and Fisheries
Date:
1919
Catalogue details

Licence: Public Domain Mark

Credit: Leaflets. Nos. 101 to 200 / Board of Agriculture and Fisheries. Source: Wellcome Collection.

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    + the turbinated bones [g, g], where they become imprisoned The larvee ejected from the nostrils pass the nymphal stage a little below the surface of the ground, under a clod, or sheltered in a tuft of grass. The fly matures and issues from the puparium during the summer, the complete develop- ment requiring about 10 months. The number of maggotsina head varies, but it is usually small. Maggots of very different sizes and in different stages of development may Le found in the head at the same time. Ben 3 The following quotation of Bracy-Clark’s, from the Volume of the Linnean Society’s Transactions, for the year 1797, describes the behaviour of. sheep when their enemy is at work :—“ The moment the fly touches the nose of the sheep they shake their heads and strike the ground violently with their forefeet, at the same time holding their noses close to the earth, they run away, looking about them on every side to see if the fly pursues ; they also smell to the grass as they go lest one should be lying in wait for them. If they observe one they gallop back or take some other direction. As they cannot, like the horses, take refuge in the water, they have recourse to a rut, dry dusty road or gravel-pits, where they crowd together during the heat of the day, with their noses held cloge to the ground, which renders it difficult for the fly to get conveniently at the nostril.” On occasion, however, the sheep may remain quite restful. Symptoms attending infestation. A discharge, which often agglutinates round the nostrils, is observed. The sheep sneeze in their endeavour to get rid of the larve. They toss their heads and rub their noses on the ground or with their feet. Sometimes they walk along with a high stepping gait and with their heads in the air. They may also exhibit difficulty in breathing from the obstruction of the air passages. There is a loss of condition attendant on the constant irritation. Treatment. In combating the sheep nostril fly prevention is to be aimed at rather than later remedial measures. 1. Attempts may be made to deter the fly from laying » its eggs or maggots by repeated dressings of the nostrils of the sheep, with such materials as tar or fish oil. As this is an onerous task, contrivances are employed for making the sheep dress themselves. These take the form of salting troughs made in the shape of the letter \/, the sides of which are smeared with tar, and as the sheep lick the salt they get the tar on their noses. In other cases the boxes containing the salt are closed, save for a hole painted over with tar.
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