A STUDY OF AGE-COMPOSITION OF NATURAL POPULATIONS OF CULEX PIPIENS FATIGANS WIEDEMANN IN RELATION TO TRANSMISSION OF FILARIASIS DUE TO WUCHERERIA BANCROFTI (COBBOLD) IN CEYLON

  • 1 January 1967
    • journal article
    • research article
    • Vol. 37  (1) , 117-+
Abstract
Filariasis due to W. bancrofti is becoming an increasingly important problem in many countries of southern and south-eastern Asia. From 1962 to 1964, a study was made of the vector of this disease, C. pipiens fatigans, in 2 districts of Colombo, Ceylon, 1 with vector control by larviciding and 1 without. Catches were made of the house-resting, biting and ovipositing populations, and the stages of ovarian development, parity and infection were determined by examination of the external appearance of the abdomen and dissection for ovariole dilatations andfilariae. About 10%-12% of the house-resting female population survivedtothe infective 2 -parous stage and about 1.5% to the 3-parous stage. Daily mortality was estimated as 13% -24% for the district with vector con -trol, and 18% -28% for that without. A field experiment based on the recapture of markedfemales confirmed these results. Biting took place indoors from 18.00 hr. to 06.00 hr. with a single peak around midnight. Most females returned to feed directly from oviposition.