This mostly means humans & rodents. When given a choice between chicken & human blood the f. molestus mosquito always prefers the human. The underground variant is also 'autogenous' meaning it can lay its first clutch of eggs without a blood-meal, requiring one only for subsequent clutches.
The London Underground Has Its Own Mosquito SubspeciesTake a bite out of this strange evolutionary examplewww.smithsonianmag.com