218 



THE AGRICULTURAL NEWS. 



July 5, 1913. 



INSECT NO^ES. 



THE BITING STABLE FLY. 



For several years past an active canipaij^n Las been 

 carried on again.st the common bouse fly {Miisfu doinestica). 



This has been the outcome of repeated .statements in 

 publications of all kinds, with regard to the known habits 

 of the insect, and its association with the distribution of 

 typhoid fever. 



More recently the biting stable tiy (Stoim-ri/s calcitrant) 

 lias been the object of much attention. The cause for this 

 Las been the circumstance that investigations have shown 

 that this insect is capable of transmitting infantile paralysis, 

 and may possibly be concerned with the transmission of other 

 diseases of man and animals. 



Interesting articles have recently appeared in the 

 Joiirmt/ of Eroiiiimic Enlnmoh'fjy On the biting stable fly 

 and the transmission of infantile paralysis, bo whii'h the 

 following references are given: — 



Tlie Relation of the Stable Fly {Siomoicija cnlcifrans) 

 to the Transmission of Infantile Paralysis, by C. T. Brues, 

 Jown. Econ. Entuin , Vol. VI, Part 1, p. 101. 



The Stable Fly {Stomoxi/s calcitninf. L.) — an Important 

 Live Stock Pest; by F. C. Bi.shop, I/ncl., p. 112. 



These sources have been freely consulted in the pre- 

 paration of the following article 



The biting stable tiy is similar in appearance to the 

 house fly to which, in fact, it is closely related, both species 

 belonging to the family Muscidae, to which also belong the 

 African tsetse tlies that convey sleeping sickness in man 

 from infected to healthy individuals. 



The biting stable tiy is an insect of European origin 

 ■which is now widely distributed throughout the world. It is 

 about the same size as the house fly and very similar in 

 general appearance to that insect It is distinguished from 

 the house fly very easily, by the painful bite which it 

 inflicts on man, and on many domestic animals — horses, cattle, 

 sheep and swine 



The breeding places of the stable fly are to be found in 

 wet and rotten straw such as that of oats, barley, rye, rice, 

 and wheat, and also in piles of old hay and weeds. Manure 

 of Lorses and cattle wLen mi.xed with a large amount of 

 straw and litter also furnish breeding places for this insect. 



During 1912, a very severe attack of this i)est occurred 

 in certain grain grfiwing districts in the Southern United 

 States. At the time referred to, the flies were so abundant 

 as to be the cause of serious logs from the injuries inflicted 

 on domestic animals and, in addition, their attacks on the 

 animals, wLen not fatal, prevented tLe ordinary farm work 

 from being carried out in the usual ininner Through the per- 

 sistent attacks of the flies, through the painful bites inflicted, 

 and through los? ol blood which naturally accompanied the 

 feeding of enormous numbers of the flies — often as many 

 as a thousand of these insects were feeding on one animal 

 at the same time — the animals suiTercd greatly from tor- 

 ment and worry. Many animals died; milch cattle fell ofT 

 in milk flow: fat animals became thin and poor. It was 

 found, too, that many cattle after experiencing severe attacks 

 of the stable fly, developed Texas fever. This was not 

 due to any infection by this insect, but rather to the 

 fact that the cattle, when in good condition, did not show 

 any effect of the presence of the pyroplasnia, already in 

 the blood, whicli causes Texas fever; but when weakened 

 bv irritation and loss of blood, the animals succumbed 



to the organisms which rapidly developed under the favour- 

 able conditions produced for them by the flies. 



'The recent attention which Las been given to the role 

 played by insects in the transmission of disease, has led many 

 investigators to consider the possibility of Storaoxys acting as 

 vector of a number of diseases of live stock and man. The 

 work of several investigators indicates that the stable fly 

 takes a more or less important part in the transmission of 

 surrah of domestic animals, a trypanosomiasis in cattle in 

 Portugese l-^ast Africa, souma {Truj".oiosomti cazalhoui) of 

 the ox, horse and sheep, T j^ca'dKi of hogs, cats, etc., and 

 anthrax in domestic animals and man. Other workers believe 

 that the fly may, in some cases, be connected with the trans- 

 mission of septicaemia in man, glanders in horses and other 

 animals and certain other maladic^. In this country [U. S. A.l 

 the recent work of .Brues and Sheppard on the apparent 

 etiological relation between Stomoxys and poliomyelitis 

 [infantile paralysis] and the work of .Jennings and King 

 pointing toward the connexion of the stable flv with 

 pellagra transmission, has had the eflect of greatly stimulatincr 

 the interest of entomologists as well as medical men in the 

 study of this insect, and its possible relation to the trans- 

 mission of various diseases, the etiology of which has not 

 been fully elucidated. As is now generally known, the con- 

 clusions of Brues and Sheppard have been greatly strengthened 

 by the work of Rosenau, which demonstrated that the stable 

 fly can transmit poliomyelitis in monkeys. The results of 

 Roseniiu have been corroborated by experiments along the 

 same line conducted by Anderson and Frost of the United 

 States Public Health Service.' 



There appear to be no records of serious outbreaks of 

 the biting stable fly in the West Indies, and, in fact, this 

 insect is definitely recorded only in Jamaica and St Vincent 

 in these islands 



The circumstances that the insect is known to occur in 

 such numbers as to be a serious pest of live stock, and that it 

 is able to transmit infantile paralysis (poliomyelitis) in man, 

 would indicate that its presence ought to be recorded wher- 

 ever it occurs: in addition to this, it is of importance in 

 connexion with the disease known as pellagra, which occurs 

 in the AVest Indies, and which, at the present time, is but 

 little understood The sand flies of the genus Simulium have 

 also been suspected of being carriers of this disease, and they, 

 too, ar.^ either generally absent from these islands, or are at 

 least not reciirded. 



West Indian readers of the A<jricidtvral K^vi are 

 invited to collect and forward specimens of any biting flies 

 which tbey may observe, together with any notes. Specimens 

 may be forwarded through the Agricultural Otticers in each 

 island. 



At a meeting of the Barbado.s Agricultural Society on 

 June 27, 191.3, a discussion arose as to the best way of 

 reducing the numbers of the brown hard back (Flii/r<tlus 

 sinitiii), which appears to be causing considerable damage to 

 sugar cane in B.irbados It was stated that the brown hard 

 back, during the earlier period of the year, is usually found 

 under old cane stumps. One member thought that' a cood 

 way of getting rid of this serious pest would be to offer 

 a prize of J?.j to the boy who produced the largest collection 

 of them at the Agricultural and Industrial Exhibition held 

 in December every year. Mr. J. R Bovell, I.S.O , F.L.S. 

 Superintendent of Agriculture, addressed the Society on the 

 subject of parasites. The one referred to of the greatest 

 importance was the small black wasp, Ti/iliin /laraUela (See 

 A'jriniltnnd X, im, Vol. XII, p. 186.) 



