Tests were conducted to determine if the preparasitic (infective) stage of the Mermithid nematode Romanomermis culicivorax Ross and Smith (=Reesimermis nielseni Tsai and Grundmann, auct., partim.) could be applied from a helicopter via a simplex low profile aerial spray system equipped with 12 TeeJet spray nozzles. Results from ground spray application at 25 psi indicated that preparasites suffered no apparent adverse effects from impact within the spray system and nozzle assemblies when compared with unsprayed preparasites, and therefore indicated that this aerial spray system would be an effective means of disseminating the preparasitic stage of R. culicivorax for mosquito control.