Gaseous Requirements for Postparasitic Development of Romanomermis culicivorax


  • J. L. Imbriani
  • E. G. Platzer


The development of postparasitic stages of Romanomermis culicivorax was studied under various concentrations of oxygen and carhon dioxide. The nematode developed poorly if only nitrogen was supplied; only one-third molted and all died eventually. In the presence of 5% CO[sub2] - 95% N[sub2], development was normal; most nematodes molted and oviposited with respective mean developmental times of 32 and 50 d. Addition of 0.2% O[sub2] stimulated development; molting and oviposition commenced at days 18 and 41, respectively. There was an additional stimulation of development by increasing amounts of O[sub2] up to 1%, but concentrations greater than 1% produced no additional stimulation. Carbon dioxide was required for development after exsheathment under anaerobic conditions or O[sub2] concentrations less than 1%. Oxygen or CO[sub2] were not required for embryological development or egg hatch. It is suggested that post-parasitic stages function as facultative anaerobes, Key words: Mermithidae, nematoda, oxygen, carbon dioxide, biological control.