Mosquito densities need to be determined in a given area at a given time by undertaking standard entomological methods such as human landing catches Or Densities per trap night etc. The value thus derived need to be substituted in the equation of BRP or vectorial capacity. There is no fixed value of mosquito densities for any given area
"Human landing catches" are useful, but being living bait can be dangerous. Some governments will not allow scientists to use HLC anymore because of the added risks, particularly if they are young and careless. HLC subjects should use protective (pesticide-treated?) clothing and headnets, or odor traps. Chicken baited flight traps, or CDC light traps, often with a light or candle reduce risk of disease. Two of our mosquito entomology PhDs went to Manaus, Brazil: The post-doc died and the other very nearly died-- of malaria. He became the U.S.A. prime authority on Lyme disease.