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.