DISTRIBUTION, BITING BEHAVIOUR, AND PRODUCTIVITY OF BREEDING SITES OF CULEX MOSQUITOES IN BADEGGI, NIGER STATE, NIGERIA

Abstract

ABSTRACT Culex mosquitoes are vectors of public and veterinary health importance as well as nuisance biters that are found widely spread all over the world. This study evaluated the distribution, biting behaviour and productivity of breeding sites of Culex mosquitoes in Badeggi, Niger State, Nigeria. Centre for Disease Control (CDC) light traps were used for the collection of adult mosquitoes while the larval mosquitoes were collected using a standard World Health Organisation (WHO) dipper (350 ml). Larval and adult Culex mosquitoes collected were identified morphologically using a standard pictorial key. Water samples were also collected and analyzed to determine the physicochemical parameters of the breeding sites (Rice field and Pond). A total of 2848 adult Culex mosquitoes were collected. Five species were encountered which include, Culex quinquefasciatus (52 %), Culex salinarius (24 %), Culex tritaeniorhynchus (17 %), Culex restuans (5 %) and Culex nigripalpus (2 %). Low biting activites was recorded between the hours of 6-7 pm and 5-6 am while the peak of biting activities was recorded between the hours of 7-9 pm. In the months of January-March, mosquitoes bit more outdoors (14 mosquitoes per night) compared to indoors (6 mosquitoes per night), in July-October, they bit more outdoors (13 mosquitoes per night) even though a considerable number bit more indoors (11 mosquitoes per night), while in the months of November-December, they bit more indoors (26 mosquitoes per night) compared to outdoors (14 mosquitoes per night). Prominent physicochemical parameters determined include; Temperature, pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Total Dissolved Solid (TDS), Total Alkalinity (TA) and Total Hardness (TH). Statistically significant difference (p˂0.05) occurred between mean pH (6.74±0.26 and 6.99±0.19), EC (258.88±22.77 us/cm and 415.75±150.81 us/cm), TA (103.63±10.79 mg/L and 124.13±20.61 mg/L), TH (78.25±10.62 mg/L and 111.50±22.58 mg/L) and TDS (100.72±31.04 mg/L and 143.72±46.37 mg/L) of rice field and pond. A Mean±SD total of 8.67±5.68 of larval mosquitoes/dip were collected, 5.48±3.72 mosquitoes/dip from pond while 3.19±1.96 mosquitoes/dip from rice-field. In conclusion, Culex quinquefasciatus is the principal Culex mosquito in Badeggi, variation occurred in the biting period and location of Culex mosquitoes. There was no significant difference in the productivity between rice field and pond. This knowledge of the active biting period and site preference should guide the deployment of appropriate control tools e.g. long lasting insecticide, treated bed nets, against these mosquito vectors.