Laboratory studies on the effect of inorganic fertilizers on survival and development of immature Culex quinquefasciatus (Diptera: Culicidae).
OBJECTIVE
Studies were conducted to determine the effect of ammonium sulfate (AM) and muriate of potash (MOP) fertilizers on survival and development of immature stages of Culex quinquefasciatus Say, a major vector of Bancroftian filariasis in Africa.


METHODS
Twenty I instar larvae each were added in four doses of each fertilizer dissolved in one litre of deionised water and in one litre of deionised water as a control in replicates of five. The larvae were monitored every morning throughout their life and the numbers of each instar surviving were recorded. The experiments were discontinued when all the larvae had died or emerged into adults.


RESULTS
An analysis of variance test and Tukey's HSD test revealed a significant impact of fertilizers on survival and development of aquatic stages of Cx. quinquefasciatus. Ammonium sulfate accounted for up to 40% mortality rate, and one week delay in development time and this effect was both instar and dose dependent. None of the MOP dosages had significant impact on survival of immatures of Cx. quinquefasciatus and only the higher dosages showed significant impact on development time but in significantly lower magnitudes compared with similar dosages of ammonium sulfate.


CONCLUSIONS
These findings demonstrate the toxic effect of fertilizers on immature stages of Cx. quinquefasciatus contrary to field observations.
Muturi
Ephantus J
EJ
Department of Medicine, William C. Gorgas Center for Geographic Medicine, Birmingham, Alabama 35294, USA. emuturi@uab.edu
Jacob
Benjamin G
BG
Shililu
Josephat
J
Novak
Robert
R
D000645:Ammonium Sulfate / Q000494:pharmacology*; D000818:Animals; D045424:Complex Mixtures / Q000494:pharmacology*; D003465:Culex / Q000187:drug effects* / Q000254:growth & development; D005308:Fertilizers; D005368:Filariasis / Q000517:prevention & control; D007300:Insect Control / Q000379:methods; D007303:Insect Vectors / Q000187:drug effects* / Q000254:growth & development; D007814:Larva / Q000187:drug effects* / Q000254:growth & development
D045424:Complex Mixtures; D005308:Fertilizers; C518454:potash; D000645:Ammonium Sulfate