82 N. J. Mosquito Extermination Association 



a total average of 16.05 animal hosts at each location, without includ- 

 ing chickens or other animals which may also serve as hosls. The 

 260.4 fed females divided among the 16.04 animal hosts gives an 

 average of 16.2 mosquitoes per animal host for each day of the five 

 summer months. This would not be the daily feeding rate if the 

 females remained more than one night around the buildings and did 

 not seek a blood meal every night. This is probably the case. The 

 rate of 16.2 Anopheles per animal host does, however, express the 

 average number of fed females found about a tenant house and its 

 out-buildings each day whether the meal had been taken one, two or 

 more nights previously. 



The June, 1920, average of 1076.2 Anopheles per house (inside 

 and under) gives an indicated total of 1395.7 mosquitoes per loca- 

 tion, from the proportions as shown in Table 1. This figure when 

 reduced by the relative proportion of males for that year (13.6%) 

 and by the per cent, of unfed females gives a daily rate for fed 

 females per animal host (including humans) of 63.1. Computed in 

 the same way the daily rate for the five summer months in 1920 the 

 number was 40.1 per animal host, and for the same five months in 

 1919 the figure was 6.4. 



SUMMARY 



1. Collections of over 132,000 adult Anopheles have been made 

 from houses and out-buildings of the negro tenants on a cotton plan- 

 tation at Mound, Louisiana. The records extend over the years 1914 

 to 1920 and have been summarized to indicate the average abund- 

 ance of malaria mosquitoes around the typical tenant house. 



2. The five summer months, May to September, were found to be 

 the months of principal abundance, with the highest rate occurring 

 in July. The average number of Anopheles found during these 

 five months resting in and around the tenant house, including the 

 out-buildings, was 344, of which about 10% were males and 90%, 

 or 310, were females. Of the females 84%, or 260, are considered 

 as having had blood meals previous to collection, the percentage 

 being taken from dissections made in 1917. 



3. The average tenant family on this plantation consists of 4.26 

 persons, and there are for each family an average of 11.79 ^f the 

 larger domestic animals (mules and horses, cows and calves, hogs, 

 and dogs). This gives a rate of 16.2 female Anopheles for each 

 host (without attempt to consider any host preference which Ano- 

 pheles of this region may or may not have). The May to September 



