78 N. J. Mosquito Extermination Association 



Anopheles crucians. A very few specimens of Anopheles pseudo- 

 puncitpennis have also been taken. As all of these species are 

 proved to be carriers of the malaria parasite, they have all been 

 included in the general averages although some differences in habits 

 have been noted. 



In summarizing the collections monthly averages were obtained 

 for each type of resting place and these monthly rates were then 

 averaged for a yearly rate or for a monthly rate for all years. 

 These averages are naturally subject to errors and one source of 

 error in our data is the fact that collections were not made uniform- 

 ly for each month in each year, also further error arises from the 

 fact that during the first few years different groups of houses 

 were examined in different months. Beginning in 1918, after the 

 preliminary work covering all the houses on the plantation had in- 

 dicated the principal resting places, 20 to 25 locations, well scat- 

 tered over the plantation, were selected and these same buildings 

 examined each month. 



Unfortunately for the value of the final averages, most of the col- 

 lections in 191 8, which was the low mosquito year in the series, could 

 not be included in the summary since they were only partial collec- 

 tions. In 1920, which was a year of extremely high mosquito 

 abundance compared with previous years, collections from the 

 stables were not made and the relative proportions of mosquitoes 

 found in these buildings in previous years was applied to the house 

 collections in 1920 in estimating the total numbers present around 

 the tenant homestead. This probably makes the figures for stables 

 too high for 1920 and in that case the average would be proportional- 

 ly high. However, the average miscellaneous collections in out- 

 buildings other than stables about the tenant houses are believed to 

 be too low, due to probable incomplete search in all places at time of 

 each collection, and the one tendancy may serve to offset the other 

 in the final averages. 



