Proceedings of Eighth Annual Meeting 8i j 



sequent changes in untrained personnel. These factors do not apply \ 

 to the collections for 1920, and it is true that the increased totals for 

 that year are due in part to the facts that all of the collections were 

 made from the same group of representative houses, that these 

 houses were collected regularly and that the work was done by the 



same personnel under careful checking throughout the season. ! 



From this it is seen that subsequent data may show the final aver- J 



ages obtained to be nearly normal, at least much nearer the normal j 



than any low year available would indicate. j 



A few of the highest collection records made during the work | 



are of interest to show what has been encountered on this plant- J 



ation in the way of maximum abundance. Four hundred and thirty- j 



five Anopheles were collected inside a four room house occupied by j 



a tenant family of eight people in 191 5, 754 Anopheles weie taken I 



from a single table in September, 1919, and 4968 were found under ■ 

 one house in June, 1920. In the last record not all of the mosquitoes 

 were collected, the remainder being counted after more than 3800 

 had been actually collected in the chloroform tubes. In 1920 this 



same house had an average of over 2000 Anopheles for each collect- 1 

 ion of the five summer months (collections made once a month). 



The June averages for all of the 25 houses which were collected ' 

 underneath in 1920 was 1040 Anopheles per collection per house 

 and these houses were all scattered over plantation with a maximum 



distance between the two farthest removed from each other of about i 

 three miles. 



The tenant houses and their out-buildings are apparently the | 



principal resting places for the engorged female Anopheles, and the | 

 majority of the specimens which have fed at night on the people or 



on the domestic animals around the place can probably be taken I 



the following day from these resting places. An idea of the amount of j 



feeding which takes place may, therefore, be obtained from the J 



above data. The average of 310 female Anopheles is taken as the , 



daily rate for each tenant house and its out-buildings. The per- \ 



centage of fed females as indicated from the dissection of over 2085 ' 



Anopheles collected at Mound in 1917 was 84%. This applied to | 



the rate of 310 reduces that figure to 260.4 fed females about each 1 



place. The average number of people in the tenant families on i 



this plantation was 4.26 for the years, 191 5, 1916 and 1917. A ^ 



count of the domestic animals at 24 places in 1920 gave totals of 53 j 



mules and horses, 32 cows and calves, 172 hogs and 26 dogs, or an j 



average of 11.79 which when added to the number of people makes j 



