348 MOSQUITOES OF NORTH AMERICA 



Not only by sailing vessels, steamships, and railroad trains are mosquitoes 

 carried without flying. Grassi has stated that he counted 200 specimens of 

 Anopheles on the inside of a stage coach during a drive lasting two hours through 

 the plains of Capaccio, and the same observer also, by the way, has recorded the 

 capture of Anopheles in a railway carriage traveling from Florence to Berlin. 

 Mr. J. K. Thibault, Jr., of Scott, Arkansas, in a letter to the senior author, states 

 that in his region mosquitoes are constantly being transported over the country 

 by buggies, covered wagons, and even, in the case of Aedes cyanescens, on the 

 backs of horses. He has known Anopheles quadrimaculatus and Culex dbomi- 

 nator to be quite frequently carried forty miles in a day, and as they will not 

 leave a vehicle while it is in motion, it will be seen that they may travel even 

 greater distances. One of the writers has never suffered more severely from the 

 attacks of mosquitoes than in a night drive in Louisiana in the autumn of 1907. 

 The stage in which he was driving for a number of miles in company with Mr. 

 W. D. Hunter, of the Bureau of Entomology, seemed filled with most vicious 

 mosquitoes which made no attempt to leave the vehicle, but remained in it from 

 the banks of the Mississippi River to the point of destination. 



Goeldi, in his " Os mosquitos no Para," expresses the belief that the steamers 

 on the river Amazon are responsible for a wholesale carriage of the yellow-fever 

 mosquito and for its general introduction into all of the small towns far up the 

 river; he attributes to this source the introduction of yellow fever at Yquitos, 

 Peru, which is practically the head of navigation. 



Balfour, at Khartoum, found that the steamers plying on the Nile were all 

 badly infested with mosquitoes, both Aedes calopus and Culex quinquefasciatus 

 breeding on them in abundance. Not only were these mosquitoes a source of 

 great annoyance to everyone on board, but by these steamers the towns along the 

 route were constantly restocked with mosquitoes. 



" For a long time it was diflBcult to control the breeding places on the steamers, 

 but in the autumn of 1904 the Director of Steamers and Boats issued more 

 stringent regulations to engineers and native reises, and the result was soon 

 apparent. Steamer after steamer arrived free from mosquito larvae, Khartoum 

 North became a more comfortable place of habitation, and the wells in the river 

 zone of Khartoum were less frequently re-infected." 



The section of the Report of Working Party No. 1, Yellow Fever Institute, 



Public Health and Marine-Hospital Service, which relates to the transportation 



of mosquitoes by ships is of much interest, since it gives the result of actual ship 



examinations at Vera Cruz and indicates how the insects are carried. It is 



quoted in full : 



" This subject was not studied in detail on account of lack of facilities, but 

 sufficient information was gathered to make it worth mentioning. The only 

 time we found mosquitoes actually breeding on board a vessel was in the instance 

 of the American schooner John H. Crandon. This schooner had arrived from 

 Mobile, Ala., with a cargo of lumber twenty days previous to our examina- 

 tion. Water and provisions had been taken on at Mobile. The examination 

 was made on account of a case of yellow fever occurring among the crew. The 

 wooden tanks were examined and found to contain larvae of Stegomyia by thou- 

 sands. The iron water tanks were examined, but owing to their depth and small 



