ZOOLOCJICAl. SOCIKIV BULLETIN 



'99 



one of the nio^t \vidc-.s])rca(l diseases afflicting; lui- 

 manity. are abundant in our midst. Aloni; our 

 Gulf Coast dwells the Slci^omya mos(|uito, the only 

 known disseminator of the ,i;erms of yellow-fe\er. 



Malaria is now believed to be res])onsible for 

 more sickness among the white population of the 

 South than any other disease, and the idea that it 

 can be spread by any other means than by mos(|ui- 

 toes is considered i)y science to be merel}' a su])er- 

 stition. The idea that mosquitoes can i)e ])ro|)a- 

 gated without water is totally without foundation. 

 Mosquitoes become troublesome wherever there is 

 stagnant water in which they can breed unmolested, 

 and stagnant pools of all kinds are therefore danger- 

 ous. 



Waters inhabited by lishes and other animals 

 which prey upon mos<|uito larva' cannot produce 

 them. Troublesome ponds may be cleared of 

 mosquito larva; by the introduction of fishes. 



The evil resulting from undrained swamps and 

 marshes is very great. Such areas can be relieved 

 of the standing water, in which mosquitoes breed, 

 by ditching, and small pools and water tanks which 

 cannot be conveniently drained or disposed of can 

 be made nioscjuito-])nH)f by covering the surface of 

 the water with oil. There is now no doui)t whatever 

 that many localities can find relief from the mos(|ui- 

 to ])lague by simple and cheap methods, while in 

 others the conditions are such that the work in- 

 voKes great e.xpense. 



There are now large numbers of medical and 

 scientific students of the mos(|uito proljlem in this 

 and other countries, who belie\e that it can be i)rac- 

 tically exterminated in many regions. The war- 

 fare against it has resulted succes.sfully in instances 

 too numerous to mention. It is being carried on 

 by boards of health, real-estate companies, town 

 corporations, private citizens, and even railroads. 

 Mosquitt)-eating fishes are being introduced into 

 public and private ponds that have caused trouble. 

 Cisterns and tanks are being ])rovided with wire 

 screens to prevent the ingress of egg-laying mostiui- 

 toes, and in many other ways enlightened com- 

 munities are finding relief from the annoyances and 

 di,seases due to mosquitoes. 



The writer has had very trying experiences with 

 mosquitoes in the .Arctic portions of Alaska. Dur- 

 ing the short .\rctic summer the cold, moss-grown 

 morasses of that region breed mos(iuitoes in vast 

 numbers, and life is almost unbearable if one is not 

 protected against them by gUnes and veils. Sleep 

 is scarcely |)ossil)le without the i)rotection of netting. 



In Arctic lands mosquitoes prol)ably pass the win- 

 ter in the larval or "wriggler" stage. It would 

 scarcely be possible for the adult insects to go 

 through the winter alive, as they flo in warmer 

 regions. There is no malaria in the far imrlh. 

 either because the mosquitoes there have never been 

 infected, it else the disease-bearin'' kind-^ d > not 



occur there. The history of malaria shows that 

 many mostiuilo-alllictcd localities never had the 

 disease until ])ersons suffering from it came there 

 and inoiulated the mos(|uitoes. This has been 

 ilemonstrated in localities to which gangs of railway 

 laborers were sent from malarial neighborhoods. 



The instruction of the jjublic at large on the 

 natural history of the mosijuito, and its connection 

 with malaria and yelk)w-fe\er, is so desirable that 

 no means of acconi]>lishing that end should be 

 neglected. The mosquito-hatching exhibit at the 

 .\(|uarium, where the attendance averages five thou- 

 sand persons daily the year round, cannot fail to 

 teach an interesting and useful le.sson. It is .seen 

 by vi.sitors from all jiarts of the country. If .such 

 a simple and inexjiensive object lesson could be 

 given for a single week in each .school in the coun- 

 try, the rising generation would be well equijjjied 

 to deal with the mo.squito trouble. 



.\ glass half full of water, containing wrigglers 

 from the nearest cistern, rain-barrel, or puddle, 

 would constitute an object lesson sufficiently strik- 

 ing to fi.x in the mind permanently the main fact 

 respecting the mosquito. Much of our effort to-da_v 

 should therefore be directed toward locating the 

 propaganda in the public schools. 



The most effective enemies of the mo.squito are 

 fishes. The Director of the .\quarium has had 

 many ajiplications for informatioji respecting the 

 kinds of fishes most available for introduction into 

 small ])onds as destroyers of mostiuito larva'. There 

 are many kinds of fishes useful for this purpose, 

 but tlie top-minnows (Finidnliis and Gii»ihiisiti) are 

 probably the best. It has been obser\-ed that the 

 common goldfish will keep ponds clear of wrigglers, 

 while sticklebacks and killifish are always u.seful. 



The young of sunfishes, shiners, perches, and 

 other common pond fi.shes doubtless are feeders 

 u])on larvic. Such fishes are found in the lakes of 

 Central and Prospect Parks, and would ])robably 

 be entirely effective for the ])ur|jose, if the shallow- 

 portions of some lakes did not become clogged with 

 jjond-weed so as to impede their movements. Top- 

 minnows are useful in such cases, as they can read- 

 ily iienetrate the weedy ]ilaces. 



It has been shown by entomologists that it is not 

 the larger park lakes well supplied with fishes 

 which give trouble, but the smaller pools to which 

 fishes do not have access. With pro])er attention 

 to the lakes and pools, our parks could be kept en- 

 tirely free from mosquitoes. 



(lood series of fresh- and brackish-water min- 

 nows, sticklebacks, and other si)ecies known to 

 feed on mosquito larva- will be kept on exhibition 

 at the .Aquarium hereafter, and will be so labelled 

 as to be satisfactory object lessons on the subject. 

 The princioal lesson to be taught in this connection 

 is that the ilU we suffer on account of the mosquito 

 are to an inviortant desiree unnecessarv. 



