Distribution and Oviposition Dynamics of Mosquito (Diptera: Culicidae) in Relation to Ovitrap Substratal Material in Minna, Nigeria

Abstract

The present study deals with o viposition responses o f m osquito populations to larval breeding habitat substrata type and subsequent effects on development and survivorship of immature life stages were elucidated in Minna, North central Nigeria. Earthen pot ovitraps, lined with different substratal material type: clay, loamy, sandy and gravel, as well as, c ontrol experiments with bare substratum, were set up in representative spatio ecological s ettings to attract ovipositing m osquitoes in the study area. Spatial distribution of the mosquito Genera encountered varied significantly among the sampling sites, with aggregate densities ranging from 28.89 8.24 larvae/ovitrap (i.e., 20.76%20.76%), to 38.61 18.61 larvae/ovitrap 27.75%27.75%). The most abundant mosquitoes in the area were Aedes 53.54 %), followed by Culex 47.74 %)%), while, the anophelines were scanty ( 0.87% The results of the oviposition behaviour indicated significant ( p<0.05 ) attraction of the ovipositing mosquitoes to ovitraps lined with earthen substrata relative to the control; as well as, significant discrim ination amongst such o vitraps. The aggregate m osquito population bred significantly ( p<0.05 ) highest in loamy ovitrap substratum 50.50 20.26 larvae/ovitrap, 31.12 %), followed by sandy ovitraps ( 34.50 8.17 larvae/ovitrap, 21.26%21.26%) and least encountered in c lay substratum ( 16.80 %). With the exception of clay substratal ovitraps that were most attractive to Aedes mosquito ( 53.21 %), all other types of substratum were most colonized by Culex individuals (range= 55.07 63.20%63.20%). Significantly higher densities of adu lt mosquitoes eclosed from loamy and clay substratal ovitraps ( 12.75 3.09 adults/ovitrap, 28.68 % and 11.25 4.35 adults/ovitrap, 25.30 %, respectively). However, proportional immature adult development success was highest ( p<0.05 ) among ovitraps lined with c lay substratum ( 41.28 %). The findings of this study suggest the need for site specific approach for mosquito vector control in Minna, with great potentials for environmental management control tactics.