The Collaborative International Dictionary of English v.0.48:

malaria mosquito \malaria mosquito\, malarial mosquito \malarial
mosquito\n.
   A mosquito that transmits the malaria parasite; it is most
   commonly the Anopheles mosquito.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

malarial mosquito
    n 1: transmits the malaria parasite [syn: malarial mosquito,
         malaria mosquito]