Concept:Filariasis (also known as Elephantiasis) is a parasitic disease caused by the nematode Wuchereria bancrofti.
It is transmitted to humans through the bite of infected mosquitoes.
Different diseases are transmitted by different mosquito vectors.
Step 1: Identify the causative organism.
The disease Filariasis is caused by the parasitic worm:
\[
\textit{Wuchereria bancrofti}
\]
Step 2: Identify the mosquito vector.
The primary vector responsible for transmitting this parasite is the
\[
\textit{Culex} \text{ mosquito}
\]
Step 3: State the final answer.
\[
\boxed{\text{\textit{Culex} mosquito}}
\]