82 ENTOMOLOGICAL NEWS. [Feb., '08 



Perhaps it is not generally known that the Florida coast is lined with 

 lighthouses. One of these lighthouses north of Key West is called Som- 

 brero. It is a frame of iron on which the dwelling and the lantern stand, 

 and is five and one-half miles from the swampy, mangrove lined shore. 

 This shore is the breeding place and home of mosquitoes. Probably no 

 unprotected human being could survive there for a single night. I know 

 well a couple who kept this light for a considerable period. Their experi- 

 ence and their testimony on the subject on which I am writing should 

 be conclusive, so I questioned them first, as to the distance that mosqui- 

 toes can smell human blood. They said that sometimes they were over- 

 whelmed with mosquitoes. Secondly, but when ? Was it when the wind 

 was blowing from the land ? Were the insects blown to you? The ans- 

 wer was that the inroads of the insects were only when the wind was 

 blowing from the lighthouse to the shore. And the keeper said "not 

 when the wind was blowing directly at right angles to the shore." I 

 suggested that there might be a pond a little out of the nearest point of 

 the shore. As to that he did not know, for I think he said he had never 

 visited the shore. 



It seems evident enough that if the mosquitoes were blown over, only 

 those embraced in the narrow zone of the width of the lighthouse would 

 ever get to the house, and as the wind never blows very long in one exact 

 direction, varying and zigzagging about, no mosquitoes would ever get 

 over the five and a half miles of water. The idea is absurd. Either the 

 insects go to the lighthouse on purpose or they don't go at all. 



Now, if a mosquito can smell warm blood five and a half miles, how 

 much farther can he smell it? The common route in pleasant weather 

 from the coast to Key West is to sail down along the shore to Boca 

 Grande. Then the vessel steers straight for its destination, a distance of 

 eighty miles. The route recedes from the land, and the distance becomes 

 as great as thirty miles. The course is regulated by sounding and the 

 vessel is not allowed to get beyond a certain depth of water. 



I am well acquainted, and have been for years, with two men who have 

 sailed across this course many times, regularly making trips from my 

 house to Key West. They say that it has happened to them time and 

 again, that they would leave Boca Grande in the evening with a westerly 

 wind. One of them would lie on his blanket on deck and sleep, while 

 the other sailed the boat. There would be no mosquitoes on the boat. 

 The sleeper would sleep undisturbed. But after a while mosquitoes would 

 appear and disturb the sleeper. When the wind began to come from the 

 east, or off shore, the insects would disappear. Those already present, 

 of course, would be either killed or quieted with blood after the way of 

 the tribe. You will take notice that these observations were made by 

 keen observers with their eyes wide open, and repeated over and over 

 again I published these facts twenty years ago. Last summer I heard 

 of an entomologist's visit to our coast and of his investigation concern- 

 ing this subject. JOHN G. WEBB, Osprey, Fla. 



