Species composition and abundance of mosquitoes of a tropical irrigation ecosystem

Abstract

Exophagic-anthropophilic mosquitoes were collected during the April 2007-January 2008 planting season in four designated mil et and guinea-corn irrigat on fields sampled in Gezawa Agro-ecological Zone of North-central Nigeria. Gezawa-1, Gezawa-2, Ketawa and Jogana irrigat on fields contributed about 31.2 %, 24.8 %, 22.8 % and 21.2% respect vely, to the number of mosquito species collected in the zone. There was preponderance of Anopheles gambiae complex (20.7 %) over Culex quinquefasciatus (11.8 %), C. pipiens fatigans (9.0%), A. funestus complex (7.0 %), Aedes aegypti (6.9%), A. albopictus (6.6 %), C. p piens pipiens (5.7 %). C tigripes (5.0%), A. pharoensis (3.7 %), A africanus (3.6%), A. taylori (3.4%), A. coustani (3.3 %), A. luteocephalus (2.9 %), A. vittatus (2.8 %), A. rhodesiensis (2.1 %) Manson a (2.0 %) A. simpsoni (1.9 %) and Psorophora species (1.6 %). A Shannon-Wiener and Simpson's diversity values of 1.1431 and 0.0925 were recorded for the mosquito species in Gezawa Agricultural Zone. A. gambiae had the highest Shannon-wiener diversity and Simpson's dominance ind ces of 0.1415 and 0.0427 respectively. There was no significant difference between species diversity for the four irrigation fields (P>0.001). Vector control must be carried out in the irrigation fields to reduce the number of these outdoor biting mosquitoes, since total reliance on ACTs and ITNs could not offer full protection against malaria to farmers in Gezawa irrigation fields. l i i i i. . , i , i