The development of Dirofilaria immitis in cultured malpighian tubules.

A technique is described for the cultivation in vitro of Dirofilaria immitis to the second larval stage within malpighian tubules excised from mosquitoes 20-24 h post infection. The malpighian tubules were removed from mosquitoes under aseptic conditions, washed and inoculated into a variety of tissue culture media, both insect and mammalian. In some cultures a feeder layer of Aedes malayensis cells was included. The 24 h larvae developed to the second stage only in Schneider's Drosophila medium containing 20% foetal bovine serum, irrespective of whether a cell layer was included in the cultures. Development of the larvae to the infective third stage was not observed.