ENTOMOLOGICAL.

Otago Witness, Issue 2056, 20 July 1893, Page 4

ENTOMOLOGICAL.

The writer is greatly obliged for the information conveyed upon the subject The Breeze o f maggots in sheep's heads in a Ply ((Estrus letter from Mr H. B. Flett, of ceplialemyia Table Hill. Mr Flett's comotls). xnunioation is valuable, because

it proves beyond doubt not only that there are maggots in this position, but that the event is one of very common occurrence and beyond any dispute, and this is a great improvement upon the hitherto vague rumours andunauthenticated paragraphs headed "Maggots in a sheep's head," many of which the writer has found to be without foundation, and many others to relate to larvae of various insects which had got into the nostrils of the sheep in various accidental ways. Here, however, we haye reliable information that there is some species of worm or larva that regularly occupies a position in the head of the sheep, although Mr Flett does not seem to think it does the sheep much if any harm. The fact of the insect being there, however, is something like the cat being in the dairy, where the famous Mr Poynter conceived it could only be after the cream — it cannot be doing any good. But with all this, we have no definite proof

that the worm described by Mr Flett is the larva of the breeze fly. The writer was some time ago applied to by the entomologist of one of the Australian Governments to say whether the breeze fly was in this colony, and whether it was a pest here to the flockowners; but although he had collected some evidence that there were instances of a larva of some kindbeing found in sheep's heads (although none so strong as Mr Flett's), he had never been able to prove, nor even to find very strong reasons to believe, that these larVffl were definitely breeze fly larvee, and therefore he Considered himself justified in reporting that up to the present time he had -not seen the breeze fly, and that if it was in the colony at all the flockowners were so very little annoyed by it that they did not seem even aware of the fact, and that it would be very inadvisable to make any arrangements respecting the importation, of New Zealand sheep, or anJr ideas re* spedting the breeze fly. Mr Flett wifl r&> member that the breeze fly larva belongs to a totally different class of animals from the worm which is occasionally found within the bones of the head, and resting upon the brain. Those are a species of hydates, a pulpy worm, which cause what is popularly known as " sturdie " in sheep. They have, in fact, very much the same effect upon a sheep as the tupakihi when the more violent attack has gone off.. It is the larva of a two-winged fly which lays its eggs on the margin of the nostrils, and these, when hatched, crawl up the nose and live on the mucous secretions. It seems hardly possible that the sheep can bo extensively affected by this fly without betraying the fact by their actions, as in other countries they rush about, bury their noses in the dust, strike with their forefeet, crowd up together with their heads down, and exhibit, several such unmistakable signs of the fly attack, of which they have the greatest dread because of the inflammation and irritation caused by the larv» crawling about amongst the bones of the nose' and inducing that irritation the effects of whioh are to produce the mucous secretions -upon whioh they feed. Perhaps Mr Flett would kindly take notice (in the interests of science) if these symptoms occur, and also compare the larvoa with this brief description. It is a whitish worm having a black or brown transverse band on each of its segments. . Its head is armed with two horny black hooks, parallel, and capable of being moved up and down, and laterally underneath. Each segment of the body has several rows of tubercles of nearly spherical form, surmounted by small bristles having reddish points. This should serve as a guide so far, and if Mr Flett would further look out about late spring or early summer, he might be able to secure the fly, when a specimen' would at once enable identification and settle the question.

Another gentleman, writing, from Hawke's Bay (d man of great experience in A Fly In sheep), says that there is a fly Hairke's there which "blows" the noieß Bay. of sheep— a somewhat curious expression— and that the maggots crawl up the nose. This certainly looks like the breeze fly ; but then he adds that when the sheep are standing in the dripping stages they are apt to sneeze, and drop the pupsa from the nostrils in considerable numbers, whereas the breeze fly larvsa do not enter the pupa state for some little time after leaving the nostril, and not in quantities at a time. Again, thtoe are other flies which deposit in the discharges of ,the nostrils when they are unhetdthy,-,and which have no connection with the breeze fly tribe. A case is aho related by Mr Harding, of Hawke's Bay (the Crown Lands Commissioner), of maggots in a sheep's horn, but the horn had been broken, and these were not breeze fly maggots.

Mr Harding further says that there have been in the Napier district all the 30 Other Sheep years he has known it flies which Fly Pests, attack sheep in very hot and close, damp weather, especially when they are sick and' lie long on the ground, and that these flies were unusually troublesome last summer. This he attributes to the fact that the weather last summer was unusually favourable to them, and not because of the advent of any new or unusual fly pest in the district. It should have been stated that the larva enters the ground to a depth of some inches deep, and does not appear until some 30 or 40 days later. Mr Bracy Clark, a good authority on the breeze fly, says that he has often taken the larvoa from " the inside of the cavities of the bone tbat supports the hornß of the sheep." The colour of the larva when very young is entirely white, and the transverse dark lines are acquired as they get older. Their size may be taken at about or nearly an inoh. long in grown specimens. Entomologist.