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Colonization of Culex gelidus theobold and some resultant effects on its biology

1962; Oxford University Press; Volume: 56; Issue: 5 Linguagem: Inglês

10.1016/0035-9203(62)90017-2

1878-3503

Herbert C. Barnett, Douglas J. Gould,

Malaria Research and Control

Interest in Culex gelidus manifested itself when Japanese encephalitis virus was isolated repeatedly from this species in Malaya. Colonization was initiated by introducing large numbers of wild, blood-engorged females into a cage containing pans of water for egg deposition. The aquatic stages were reared in pans by conventional techniques and the adults were maintained in two types of cages. Blood meals for the females were provided by offering human beings and pigs on alternate days. Temperature of 27–28°C., relative humidity of 80 per cent. and artificial lighting provided satisfactory environmental conditions for the adults. When initial attempts were made to subcolonize the species in the United States all adult material went into a state of diapause. Subsequent lenghtening of the "day" period and installation of an exhaust fan in the insectary eliminated this problem. In retrospect, it is not clear whether the problem of diapause was related to the phenomenon of photoperiodicity or to the level of carbon dioxide in the atmosphere of the insectary. In studies on the effect of colonization upon the biology of the mosquito, only changes in the reproductive biology could be detected. Extensive alteration of reproductive behaviour occurred early in the process of colonization, but a gradual return to the "wild" condition took place over four generations.