Role of some environmental factors on the breeding activity of Anopheles arabiensis in New Halfa town, eastern Sudan

Anopheles arabiensis breeding was studied during March 1999–June 2000 in New Halfa town. Of 3642 anopheline larvae collected, 3633 (99.75%) were A. arabiensis: 82.49%, 11.56%, 3.08% and 2.88% of the larvae were collected from shallow sunlit pools resulting from pipes leakages, rain pools, irrigation canals and man-made pools respectively. The overall mean density was 24.34 larvae/ 10 dips: 40.73 during the rainy season, 30.45 during irrigation and 13.10 in the dry season. Water for crop cultivation increased the relative humidity (P = 0.013) and both factors enhanced A. arabiensis breeding (P 0.005). There was no significant difference between the rainy and irrigation seasons. A. arabiensis breeding in this area has become perennial as a result of crop irrigation.