Page:The New International Encyclopædia 1st ed. v. 10.djvu/754

* INSECTS. 6C6 INSIDIOUS FLOWZR-BUG. permanganate of potash, one to 1500, was found tu he as effective, though not as clieap, as i>e- tioleiini. It lias heon ascertaineil that goldfish niay he used as the agent for the destruction of the' larva' of mosquitoes, as they eat them eagerly. Extensive and important studies in New Jer- sey established the facts that the most abundant species of mosquitoes in that State. Vtilejc sot- licitaiis, breeds not only in brackish and salt water, but also in water that is '2o per cent, more salty than ordinary sea-water; that it docs not breed in fresh water at all; that adult mosquitoes may !« found in great abundance from 20 to 40 miles from their breeding-places; and that mosquitoes occur from 5 to 15 miles oil' shore, over the open ocean, at points to which they have lx>en carried by the wind. Ciilex pun- geu's, next in abundance to Culex sollicitans, was found breeding in every place where water is not salt. The breeding time for these mosquitoes is late in the fall, and the adults hibernate. In the opinion of the expert observers who have investigated the matter, the mosquito is also responsible for the transmission of yellow fever. This theory was first advanced by Dr. Carlos Finlay, of Havana, in 1881. Uecd. Carroll. Agra- monte, and Lazear. who formed the commission appointed in 1900 by the Surgeon-General of the United States Army to investigate yellow fever in Cuba, concluded that the mosquito serves as the intermediate host for the. ])arasite of yellow fever and that it is highly probable that the dise.ise is propagated only through the bite of this insect. Culex fasciiitus, which is identical with Culex tiniads (Giles), is the mosquito that acts as host for yellow fever. Xo less an author- ity than Dr. John GuitOras, formerly an oppo- nent of this theory of the transmission of yellow fever, has Iwcome its earnest advocate. The mos- quito has a part. also, in the dissemination of lepros}-. Kaposi has instanced a case of this disease, easily traceable to a mosquito-bite. The ex-periments of Alvarez, as quoted by Carmichael, support this theory of mosquito transmission in leprosy. It is admitted without reserve that filariasis is transmitted by mosquitoes. Cor- roborative experiments and studies in the devel- opment of filaria noeturna were made by Low, of Rome, Italy, in 1001. He found active filaria ombrvos in the thoracic muscles of Culex territi- tus between twelve and twenty-four hours after this mosquito had fed on a patient suffering from filariasis. In Culex fasciatufi he found per- fected filariip in the head, neck, and proboscis. F.lephantiasis has been transmitted by the mos- quito. Its parasite was found in their bodies by the investigations of the Liverpool School of Tropical Medicine in Nigeria, Africa, in 1000. The fill is properly charged with the trans- mission of many diseases. Nuttall fed the bacil- lus of the bubonic plague to flies, and ascertained that they convey the infection to man. Car- michael believes that leprosy is communicated by the same insect. The bacilli of anthrax (malig- nant pustule) have been found in flies. Grassi, of Milan, and, much later. Beale, of Calcutta, demonstrated that cholera was a fly-borne dis- ense, and the genns of typhoid fever ore carried by the same insect which swarms over f;pcal evacuations. Hervieux. of France. ascril>ed the spread of smallpox to flies. Simond's investiga- tions, carried on during 1899, together with the results obtained by Yersin, favor the theory of the spread of plague from rat to man by the flea. ISu-ck charges the iteh-iiiile (q.v.) with being an active agent in the spread of leprosy. Smith and Kilbourne established the fact that the tick propagates Texas fever among sheep. The bacilli of anthrax have been found in earth- icornii. Kobler"s experiments led him to accuse the ant of carrying the infection of bubonic jilague to man. From a sheep that died of niitlirax. in Cyprus, in 1001, ants transmitted the fatal dis- ease to a woman in a cottage near by. Ilonihcs are believed to carry typhoid fever in the same way as do Hies. The bedbuq is responsible for the spread of leprosy (Carmichael), cancer (Moran). tuberculosis (Denevre), and relapsing fever (Titkin). Insects, it is seen, propagate diseases in two ways: (1) As carriers, bringing infection to a wound or to fooil and drink on the surface of their bodies, after crawling over an infected spot, or bringing the infection in the form uf bacilli in their intestinal tracts; (2) as intJT- mediary hosts, bringing to the victim the infec- tion in the fluids of their bodies and inflicting wounds through which the poison is introduced into the body of the victim. The mosquito is a true intermediary host. Flies and llcas are examples of carriers. Coplin, of Philadel])hia, experimenting in the line of the researches of Sangr?s. caused ruachcs, flies, and bedbugs to walk over cultures of various disease germs and then to walk over sterile agar plates, many hours later, having been kept in the meantime in large jars, under as natural conditions as possible. Examinations of the agar plates made subsequently showed active cultures of the va- rious bacilli of infection. The feet, the ventral portion of the body, and the wings of insects carry infection and plant the disease organisms in rows and small colonies throughout the sur- face of the sterile plates. Forty-eight hours of continuous infectivity was shown in the case of many disease germs thus transmitted. In one case the typhoid bacilli carried on the body of a roach retained their virulence for ninety-six hours. But one germicide has proved of avail in dis- infecting bacteria-laden material, and this is formaldehyde. The great difficulty in rendering harmless the insect carrier of disease is easily appreciated. Consult: Ross, Malarial Fever: Its Cause, Prevention, and Treatment (Liverpool, 1902) ; Low, Pa/iers on Malaria and Filariasis (George- town, Demarara, 1901); Cornoldi, La mosca e il colera (Venice, 1884) ; Beale, Cholera a Fl;/- Borne Disease (Calcutta, 1897); Jloore, "Flies and Disease," in Medical Magazine (London, 180.3-94 ) ; Howard, "Carriage of Disease," in Miscellaneous Ucsults (Washington, 1901) ; Nut- tall, Hygienic Measures in Relation to Infectious Diseases (New York, 1803) ; Grassi, Die Mala- ria (Jena, 1901); Celli. Malaria According to the Xew Researches (London. 1001); Liverpool School of Tropical Medicine, Memoir III., Report of the Malarial Expedition to yigeria (Liver- pool. 1001). INSIDIOUS FLOWEB-BUG. A minute heteropterous insrct {Triphleps insidiosus) com- mon in the United States. It belongs to the