Comparative assessment of immature survivorship and developmental duration of Culex pipiens pipiens (Diptera: Culicidae) populations in north central Nigeria.

Abstract

Background: Culex mosquito vectors of human diseases have received relatively lesser attention from mosquito biologists even though the diseases transmitted by these mosquitoes rank foremost among public health challenges worldwide. As a result, very little is known about spatial ecology of these mosquitoes, especially, the dynamics of their larval development; an important factor that governs the success of larviciding measures. This need informed the present study to elucidate spatial variations in survival and developmental rates of Culex pipiens pipiens mosquito populations in North Central Nigeria. Methods Day old larvae of Culex pipiens pipiens mosquitoes were collected from four widely-spaced localities in the area namely; Gidan Kwano (A), Bosso (B), Maikunkele (C) and Chanchaga (D). The larvae were reared under laboratory conditions and monitored for immature life-stage survival and developmental rates, following standard procedures. Results The results indicated that Total Immature Survival Rate (TISR) was very high (>88%), though varied significantly (P<0.05); ranging from 88.67±7.58% in site C to 95.08±1.68% in site D. While, Pupal Stage (PS) survivorship varied significantly (range = 86.92±12.16 to 97.24±2.48%), those of Total Larval Stage (TLS) (Range = 86.76±7.99% to 93.39±4.48%) were insignificantly different (P>0.05) among the sites. The fastest developing immature population of Cx. p. pipiens in the area was that from site C, which took 8.67±2.03 days. This value was significantly lower than those from other sites; taking as long as 10.10±0.94% days in site B. Conclusion These results revealed significant spatial variation in survival and developmental rates of immature Cx. p. pipiens populations in north central Nigeria; and such variations appear to be driven by endogenous factors. This spatial heterogeneity may influence the vectorial importance and ecological adaptations of the species in the area, and therefore demand site-specific larval vector control strategies and intervals in the area.