, Volume 19, Issue 4, pp 409–420 | Cite as

Mass release effects ofchlorohydra viridissima [Coelenterata] on field populations ofAedes nigromaculis andCulex tarsalis in Kern County, California

  • Hyo-Sok Yu
  • E. F. Legner
  • R. D. Sjogren


European green hydra,Chlorohydra viridissima (Pallas) were tested for adaptability and predation effectiveness in natural habitats ofAedes nigromaculis (Ludlow) andCulex tarsalisCoquillet in Kern County, California from June through December, 1973. Hydra were well adapted to all habitats except Kern River seepage where their adaptability was measured at only 55.6%.Aedes nigromaculis populations were reduced 67.2% in an irrigated pasture in July.Culex tarsalis densities were reduced 33.9% in standing Kern River seepage and 79.2% in duck club ponds from September through December, 1973. TheC. tarsalis larval density in hydra treated duck club ponds remained below an average of 0.5/dip after inoculation in September. Hydra density increased at inoculation sites and significant numbers overwintered at Riverside, California without food. The practical utilization of hydra and their attributes for mosquito control are discussed.


Plant Pathology Natural Habitat Practical Utilization Field Population Larval Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


L'hydre verte européenne,Chlorohydra viridissima (Pallas) a été expérimentée de juin à décembre 1973 quant à ses possibilités d'adaptation et son efficacité prédatrice dans les habitats naturels deAedes nigromaculis (Ludlow) etCulex tarsalisCoquillet dans le comté de Kern en Californie. Les hydres se sont bien adaptées à tous les habitats, sauf dans les infiltrations de la Kern River où leur adaptabilité a été évaluée à 55,6 % seulement.

Les populations deA. nigromaculis ont été réduites en juillet de 67,2% dans une prairie irriguée, celles deC. tarsalis ont été réduites de 33,9% dans des infiltrations stagnantes de la Kern River et de 79,2% de septembre à décembre 1973 dans des mares à canard. La densité des populations larvaires deC. tarsalis dans les mares à canard traitées à l'aide des hydres est restée inférieure à une moyenne de 0,5 par prélèvement après l'intervention en septembre. La densité en hydres s'est accrue dans les lieux d'introduction et des quantités significatives ont passé l'hiver sans alimentation à Riverside, Californie. L'utilisation pratique des hydres et leurs propriétés pour la lutte contre les moustiques sont discutées.


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Copyright information

© Le François 1974

Authors and Affiliations

  • Hyo-Sok Yu
    • 1
  • E. F. Legner
    • 1
  • R. D. Sjogren
    • 2
  1. 1.Division of Biological ControlUniversity of CaliforniaRiverside
  2. 2.Kern Mosquito Abatement DistrictBakersfield

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