Mosquito
Mosquitoes of the genus "Toxorhynchites" never drink blood. This genus includes the largest extant mosquitoes, the larvae of which prey on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents, with varying success.
Rocio viral encephalitis
"Psorophora ferox" was the only mosquito species directly implicated in transmission through detection of virus in specimens collected at the outbreak site, but species of "Culex" ("Melanoconion"), "Coquillettidia chrysonotum", "Mansonia indubitans", "Ochlerotatus scapularis", "Ochlerotatus serratus", and other mosquitoes in Tribes Culicini, Anophelini and Sabethini were also present in those collections. Studies with mosquitoes from the epidemic zone after the outbreak showed that "Psorophora ferox" and "Ochlerotatus scapularis" could be classified as potential vectors, but "Ochlerotatus serratus" was relatively insusceptible. Field investigations in the late 1970s and 1980s showed that "Ochlerotatus scapularis", "Ochlerotatus serratus" and species of "Culex" ("Melanoconion") were the predominant mosquitoes in the epidemic zone, and that "Ochlerotatus scapularis" was the most common and abundant mosquito in human settlements and human-made environments. Outside the epidemic zone, laboratory studies have shown that "Culex tarsalis" mosquitoes from Arizona and "Culex pipiens pipiens" mosquitoes from Illinois were relatively efficient experimental vectors; Tennessee "Culex pipiens" subspecies and Argentina "Culex pipiens quinquefasciatus" were moderately efficient experimental vectors; Louisiana "Psorophora ferox", and "Culex nigripalpus" and "Culex (Melanoconion) opisthopus" from Florida were relatively inefficient experimental vectors. "Psorophora ferox" and "Aedes scapularis" were shown to be susceptible to per os infection with Rocio virus and could transmit the virus by bite following an incubation period, whereas infection rates in "Ochlerotatus serratus" did not exceed 36% and an ID50 could not be calculated for this species so it is unlikely to be an epidemiologically important vector of Rocio virus.