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DISEASE-BEARING INSECTS IN SAMOA. 

 By R. W. Doane. 



Stanford University, California. 

 (Plates XXTX-XXXI.) 



A short stay on the island of Upolu, German Samoa, during the summer of 

 1913, afforded an opportunity to make a few observations on mosquitos and flies, 

 which I wish to record. As practically all my time was taken up with another 

 problem, only fragmentary notes could be made on these insects. 



As in many of the Pacific Islands, Stegomyia fasciata, S. pseudoscutellaris and 

 Culex fatigans vie with each other for supremacy in point of numbers and in the 

 amount of irritation they can cause the inhabitants. As soon as the visitor 

 reaches his room at his hotel he finds S. fasciata there to greet him, and from 

 morning until night her attentions are untiring as long as he is around the house, 

 particularly if he sits down to read or to do a piece of work in his laboratory. 

 A siesta is out of the question without the protection of a mosquito net. 



The natives pay but little attention to this mosquito, seeming to take it as one 

 of the necessary things of life, and most of the white residents soon assume much 

 the same attitude toward the pest. But the newcomer is often annoyed almost 

 beyond endurance, and usually makes some effort to combat the tormentor. He 

 soon finds, however, that this insignificant-looking little black mosquito is not 

 like the mosquitos with which he is familiar in colder climes, for it approaches 

 quietly from the rear or on the shady side and sings its high-pitched song of 

 triumph after, and not before, it has feasted. It has a wonderful faculty for 

 finding the thin spots in one's clothes, and delights to feed on your ankles as you 

 sit with your feet under the table or desk. Its long association with man has 

 made it wondrous wise. 



After trying many things we found that most relief could be had by simply 

 taking time to go after and capture the mosquitos in the room with an insect net. 

 The few stragglers that escape in the first round-up, or that come into the room 

 later, can be captured one at a time, if the insect net is close at hand while one is 

 at work. 



On account of the frequent and heavy rains and because of the lack of any 

 sewage system, there are always plenty of places for the mosquitos to breed 

 around the houses, and as a rule little or no attempt is made to control the 

 number of mosquitos by limiting the number of breeding places. Spasmodic or 

 half-hearted control measures will do but little good. In a house that was 300 

 feet or more from its nearest neighbour all the cisterns were covered with double 

 screens and the tin cans and broken bottles in the immediate vicinity of the 

 house were emptied ; but no relief was obtained. Climbing to the roof of the 

 house I found that one of the eaves-troughs had sagged somewhat just over my 

 laboratory window and in the little water that had collected there the mosquitos were 

 breeding abundantly (Plate XXIX). As the adults issued they could easily pour 

 through the open window into the house, for no door- or window-screens are used 



