August, 1908.] 



141 



LIVE STOCK. 



THE DESTRUCTION OP 

 MOSQUITOES. 



(To the tiditor of the " Times.") 

 Sir, — Any suggestions or discoveries 

 that help towards the destruction of 

 mosquitoes and other insect pests in 

 their larva stage at e of such great im- 

 portance that I venture to ask you to 

 give me a small space in which to record 

 some results which have been attained 

 in the West Indies. 



It has long been known that Barbados 

 is the only West Indian island that is 

 absolutely free from malaria and from 

 the presence of the anopheles mosquito. 

 Major Hodder, r.b., in his reports to the 

 War Office three years ago on the drain- 

 age works that were then being carried 

 out in St. Lucia, came to the conclusion 

 that there was some hitherto undis- 

 covered reason why the anopheles failed 

 to propagate its kind in Barbados, where 

 the culex was abundant. It appeared 

 from this observation that the 

 anopheles could, or did, only breed on 

 the ground level ; none of its larvae 

 being found in tanks which were raised a 

 few feet from the earth, nor even on 

 those which were actually resting on the 

 ground. The culex can, on the other 

 hand, breed in the gutters on the roofs 

 of high buildings as easily as in the low- 

 lying swamps and pools. My friend Mr. 

 C. Kenrick Gibbons, who had given a 

 good deal of attention to the mattei\ 

 pointed out at once that all the pools and 

 swamps in this island were stocked with 

 swarms of a tiny fish (known locally, 

 from their vast numbers, as " millions '"'), 

 and that their favourite food was the 

 larvae of the mosquito. It is obvious that 

 any species of that insect which is unable 

 to breed above the ground level must fall 

 a prey to this enemy. The fish has been 



identified by Mr. Boulenger, p.r.s., of 

 the British Museum, as Girardinus 

 poceiloides. Some specimens are success- 

 fully got to England, and flourished for 

 some time in the insect house at theZooIo- 

 gical Society's Gardens. Mr. Gibbons' 

 suggestion that the "millions" should be 

 imported into malarial districts in other 

 islands has been acted upon, and with 

 felicitous results. For instance, the 

 Country Health Board of Antigua, 

 "being convinced of the useful part 

 played by these fish in consuming 

 mosquito larva?, have arranged for their 

 systematic destruction throughout the 

 ponds and streams of the islands." 

 Similar news comes from Jamaica, 

 whither a consignment of the fish was 

 sent in November, 1906. The Secretary 

 of the Agricultural Society writes that 

 the tanks at the Titchfield Hotel are full 

 of them, and that he had been informed 

 that " there has been a marked diminu- 

 tion of fever round about, the ' millions ' 

 evidently accounting for the mosquito 

 larvae." They have also been sent to 

 Colon and British Guiana, One cannot 

 help wishing that these useful little fish 

 were given a trial in the deadly districts 

 of Africa, if, like the material mosquito, 

 the insects which convey the terrible 

 diseases which are endemic there, pass 

 the larvae stage of their existence in 

 water. One may add in this connection 

 that the Swedish Consul at Frankfort 

 has discovered a small fish ("the blue- 

 eyed ") which feeds on mosquito larvae, 

 and that, at the request of the Italian 

 Government, some are to be, or have 

 been, sent to the Campagna, where so 

 much has been done in recent years to 

 diminish malaria. 



I am, Sir, your obedient servant, 



T. HERBERT BINDLEY. 



Codrington College, Barbados. March. 1908. 



