ABSTRACT
Background & objectives: Accurate mosquito species identification is the basis of entomological surveys and effective vector control. Mosquito identification is either done morphologically using diagnostic features mentioned in taxonomic keys or by molecular methods using cytochrome oxidase subunit 1 (coxI) and Internal transcribed spacer 2 (ITS2). Methods: We performed a larval survey for Aedes mosquitoes from eight different geographical regions in Tamil Nadu, India. The mosquitoes collected during the survey were characterized using both morphological and molecular markers. Results: During an entomological survey from eight different geographical regions in Southern India, a morphological variety named Aedes aegypti var. luciensis was observed. The variant mosquitoes were characterized using both morphological and molecular markers. The variant mosquitoes differed only in the dark scaling of 5th segment of hind-tarsi. Around one third to two third of the 5th segment in variant mosquitoes was dark which has been described as white in identification keys. No other significant difference was observed in adults or immature stages. The variation was heritable and coexisting in the field with the type form mosquitoes. Comparison of the genetic profile of coxI and ITS2 were similar in variant and the type form indicating both of them to be conspecific. Interpretation & conclusion: The morphological variant mosquitoes were found genetically similar to the Ae. aegypti type form. However, considering its high prevalence and coexistence with Ae. aegypti type form in different geographical regions, detailed studies on bionomics, ecology, genetics, behavior as well as its plausible role in disease transmission are warranted.
ABSTRACT
A rapid dot enzyme immuno assay (Dot ELISA) for rabies antibody estimation has been standardized in which nitrocellulose sheet has been used as a solid support absorbing a commercial tissue culture rabies vaccine as antigen. The test was compared with a standard plate ELISA test. The results were comparable and the student "t' test for proportion revealed that plate ELISA test is significantly better (P 0.05) when compared to Dot ELISA for the number of sera with titre < 0.5 Iu/ml and in the case of > 0.5 IU/ml Dot ELISA is found to be better over plate ELISA test at the same significance level.