Biomedical subjects
N Rishikesh
Publications and source records attributed to N Rishikesh.
Seasonal variations in indoor resting Anopheles gambiae and Anopheles arabiensis in Kaduna, Nigeria.
A longitudinal study in a guinea savanna area in Northern Nigeria showed that indoor resting samples consisted almost entirely of An. gambiae in the wet season, characterized by relatively lower temperature and higher relative humidity, whereas An. arabiensis predominated in the dry season, characterized by relatively higher temperature and lower relative humidity. A significant change was also observed in the frequency of polymorphic chromosomal inversions in the population of An. gambiae. The inverted arrangements 2Rbc, 2Rd and 2La were found more frequent in the dry season samples as compared to the wet season ones.
Hut entry and exit by Anopheles gambiae and Anopheles funestus in an unsprayed village near Kaduna in Northern Nigeria.
Hut entry and exit by An. gambiae and An. funestus were studied in an unsprayed village near Kaduna in Northern Nigeria. A high turn-over of indoor resting mosquitoes of all blood digestion stages was noted throughout the night. The behaviour of both species was similar. The entry pattern was more uniform than the exit which showed two distinct peaks around sunset and after midnight. Most of the daytime resting mosquitoes left the huts during the first hour after sunset, and therefore the mosquitoes escaping during the subsequent hours of the night were mainly those that had entered the same night and spent only a limited period inside the huts. The significance of the movement of mosquitoes is discussed in relation to entomological evaluation of the impact of residual insecticides.